RBSE Solutions Class 5 Maths Chapter 11 Time Important Questions

Rajasthan Board RBSE Class 5 Maths Chapter 11 Time Additional Questions

Multiple Choice Questions

Question 1. In one minute
(a) 80 seconds
(b) 60 seconds
(c) 40 seconds
(d) 20 seconds
Answer: (b) 60 seconds
In simple words: One minute is the same as 60 seconds. This is a basic unit of time conversion.

🎯 Exam Tip: Remember common time conversions like 1 minute = 60 seconds and 1 hour = 60 minutes for quick calculations.

Question 2. Time of 60 minutes is called-
(a) 1 minute
(b) 1 second
(c) 1 hour
(d) None of the options
Answer: (c) 1 hour
In simple words: When 60 minutes pass, it is equal to one hour. This is how we measure longer periods of time.

🎯 Exam Tip: Always relate minutes to hours and seconds to minutes to understand how different time units connect.

Question 3. Total minutes in 2 hour 30 minute
(a) 150
(b) 120
(c) 60
(d) 180
Answer: (a) 150
In simple words: To find total minutes, change hours into minutes first (2 hours \( \times \) 60 minutes/hour = 120 minutes) and then add the remaining minutes (120 + 30 = 150 minutes).

🎯 Exam Tip: Break down mixed time units (like hours and minutes) into a single unit (minutes) for easier calculation.

Question 4. Total seconds in one hour is
(a) 3600 seconds
(b) 360 seconds
Answer: (a) 3600 seconds
In simple words: There are 60 minutes in an hour, and each minute has 60 seconds. So, multiply 60 by 60 to get the total seconds in an hour, which is 3600.

🎯 Exam Tip: To convert hours to seconds, multiply by 60 (for minutes) and then again by 60 (for seconds), so it's hours \( \times \) 3600.

Question 6. Time of 645 seconds is
(a) 64.5 minutes
(b) 10 minutes 45 seconds
(c) 6 hour
(d) 15 minutes
Answer: (b) 10 minutes 45 seconds
In simple words: To convert seconds to minutes, divide the total seconds by 60. The whole number part is minutes, and the remainder is seconds.

🎯 Exam Tip: When converting smaller time units to larger ones, use division. For example, seconds to minutes involves dividing by 60.

Question 7. Seconds in 18 minutes are
(a) 108 seconds
(b) 180 seconds
(c) 1080 seconds
(d) 1800 seconds
Answer: (c) 1080 seconds
In simple words: To find the total seconds in 18 minutes, multiply 18 by 60, because there are 60 seconds in every minute. This gives 1080 seconds.

🎯 Exam Tip: When converting larger time units to smaller ones, use multiplication. For example, minutes to seconds involves multiplying by 60.

Question 8. Largest unit of time measurement in the following is
(a) seconds
(b) minutes
(c) metre
(d) hour
Answer: (d) hour
In simple words: Out of the choices given for time measurement, an hour is the longest amount of time. A metre is a unit for length, not time.

🎯 Exam Tip: Be careful not to confuse units of time with units of length or other measurements. Always check if the options make sense in the context of the question.

Question 1. In the following, fill in the blanks:
(1) The dial of a watch is divided into ............ big parts.
(2) Smallest unit of time measurement is ............
(3) Value of 60 seconds is equal to ............
(4) To convert hour unit into minute unit, multiply by ............
(5) To convert hour unit into second unit, multiply by ............
Answer:
(1) 12
(2) seconds
(3) 1 minute
(4) 60
(5) 3600
In simple words: This question tests basic knowledge about watches and how to convert between different units of time. A watch face usually has 12 main numbers, seconds are the smallest common unit, 60 seconds make a minute, and multiplying by 60 or 3600 helps convert time units.

🎯 Exam Tip: Memorize standard time conversions (1 minute = 60 seconds, 1 hour = 60 minutes, 1 hour = 3600 seconds) for quick recall.

True/False

Question 1. Identify true and false statements
(1) 260 minutes = 4 hour 20 minutes
(2) 5 hour 40 minutes = 350 minutes
(3) 40 minutes = 40 \( \times \) 60 seconds = 4200 seconds
(4) There are 720 minutes in 1 day.
Answer:
(1) True
(2) False
(3) False
(4) False
In simple words: This question checks your ability to convert between hours and minutes and to calculate total minutes in a day. You need to remember that 1 hour is 60 minutes and 1 day is 24 hours.

🎯 Exam Tip: Always double-check your conversions by performing the multiplication or division step-by-step to avoid errors.

Question 2. Identify true and false statements
(1) We multiply hour unit by 60 to change it in minute unit.
Answer:
(1) True
In simple words: To change a number of hours into minutes, you simply multiply the hours by 60, because each hour has 60 minutes.

🎯 Exam Tip: Always remember that when converting a larger unit to a smaller unit (like hours to minutes), you multiply; when converting a smaller unit to a larger one (like minutes to hours), you divide.

Question 3. Identify true and false statements
(1) On subtracting 1 minute 40 seconds from 3 minutes 10 seconds we get 1 minute 20 seconds.
(2) 4 hours = 240 minutes.
(3) The dial of a watch is divided into 12 big parts.
(4) Smallest unit of time measurement is minute.
Answer:
(1) False
(2) True
(3) True
(4) False
In simple words: This question checks your understanding of time subtraction, hour-minute conversion, and basic watch parts. It also reminds you that seconds are smaller than minutes.

🎯 Exam Tip: When subtracting time, you might need to "borrow" from the larger unit (e.g., 1 minute from minutes becomes 60 seconds added to seconds).

Question 4. Identify true and false statements
(1) Largest unit of time measurement is hour.
(2) We have 4 minutes 14 seconds on subtracting 11 minutes 24 seconds from 15 minutes 38 seconds.
(3) 645 seconds = 11 minutes 45 seconds.
(4) 5 hours = 345 minutes.
Answer:
(1) False
(2) True
(3) False
(4) False
In simple words: This question tests your knowledge of time units, subtraction, and conversions. A day is a larger unit than an hour, and 5 hours is equal to 300 minutes, not 345 minutes.

🎯 Exam Tip: Always be careful with time conversions and subtractions. Remember that 1 minute has 60 seconds and 1 hour has 60 minutes. Also, 1 day has 24 hours.

Very Short Answer Type Questions

Question 1. Convert 4 hours into minutes.
Answer:
We know that 1 hour = 60 minutes.
So, to convert 4 hours into minutes, we multiply 4 by 60.
4 hours \( = 4 \times 60 \) minutes \( = 240 \) minutes.
Therefore, 4 hours is equal to 240 minutes.
In simple words: Since each hour has 60 minutes, you multiply the number of hours by 60 to find the total minutes.

🎯 Exam Tip: For conversions between hours and minutes, remember the key relationship: 1 hour = 60 minutes. Use multiplication for hours to minutes and division for minutes to hours.

Question 2. How many minutes are there in 3 hours?
Answer:
We know that 1 hour has 60 minutes.
So, to find the minutes in 3 hours, we multiply 3 by 60.
3 hours \( = 3 \times 60 \) minutes \( = 180 \) minutes.
Therefore, there are 180 minutes in 3 hours.
In simple words: You multiply 3 by 60 because each hour is made of 60 minutes.

🎯 Exam Tip: Always remember that 1 hour equals 60 minutes. This is a fundamental conversion for all time-related problems.

Question 3. Convert \( 3\frac{1}{2} \) hours into minutes.
Answer:
First, convert the mixed fraction into an improper fraction:
\( 3\frac{1}{2} = \frac{(3 \times 2) + 1}{2} = \frac{6 + 1}{2} = \frac{7}{2} \) hours.
Next, we know that 1 hour = 60 minutes.
So, to convert \( \frac{7}{2} \) hours into minutes, we multiply by 60:
\( \frac{7}{2} \times 60 \) minutes \( = 7 \times 30 \) minutes \( = 210 \) minutes.
Therefore, \( 3\frac{1}{2} \) hours is equal to 210 minutes.
In simple words: Change the mixed number to an improper fraction, then multiply it by 60 to get the total minutes. For example, half an hour is 30 minutes, so three and a half hours is 180 + 30 = 210 minutes.

🎯 Exam Tip: When dealing with mixed numbers in time conversions, always convert them to improper fractions first for easier multiplication.

Question 4. Convert 3 minutes into seconds.
Answer:
We know that 1 minute has 60 seconds.
To convert 3 minutes into seconds, we multiply 3 by 60.
3 minutes \( = 3 \times 60 \) seconds \( = 180 \) seconds.
Therefore, there are 180 seconds in 3 minutes.
In simple words: Since each minute has 60 seconds, you just multiply the number of minutes by 60 to find the total seconds.

🎯 Exam Tip: Remember this basic conversion: minutes \( \times \) 60 = seconds. This is often used in daily life calculations.

Question 5. How many seconds are there in 7 minutes?
Answer:
We know that 1 minute is equal to 60 seconds.
To find out how many seconds are in 7 minutes, we multiply 7 by 60.
7 minutes \( = 7 \times 60 \) seconds \( = 420 \) seconds.
So, there are 420 seconds in 7 minutes.
In simple words: Multiply the number of minutes by 60 to get the total number of seconds.

🎯 Exam Tip: Always clearly state the conversion factor (e.g., 1 minute = 60 seconds) before performing the calculation for clarity.

Question 6. Convert 1 hour into seconds.
Answer:
We know that 1 hour is equal to 60 minutes.
And 1 minute is equal to 60 seconds.
So, to convert hours to seconds, we first convert hours to minutes, then minutes to seconds.
1 hour \( = 1 \times 60 \) minutes \( = 60 \) minutes.
Now, 60 minutes \( = 60 \times 60 \) seconds \( = 3600 \) seconds.
Therefore, 1 hour is equal to 3600 seconds.
In simple words: To convert an hour to seconds, you multiply by 60 twice: once to get minutes, and again to get seconds. So, 1 hour is 3600 seconds.

🎯 Exam Tip: Remember that 1 hour directly converts to 3600 seconds. This is a common conversion, so knowing it can save time in exams.

Short Answer and Essay Type Questions

Question 7. Amrita worked sewing a total of 5 hours in 2 days. If she has done sewing 2 hours 53 minutes on the first day, tell how much time sewing work the other day she did?
Answer:
Total time Amrita worked over 2 days = 5 hours 00 minutes.
Time she worked on the first day = 2 hours 53 minutes.
To find the time worked on the second day, we subtract the time worked on the first day from the total time.
We need to subtract 2 hours 53 minutes from 5 hours.
Since we cannot subtract 53 minutes from 00 minutes, we borrow 1 hour from 5 hours. 1 hour is 60 minutes.
So, 5 hours becomes 4 hours and 60 minutes.
Now we subtract:
4 hours 60 minutes
\( - \) 2 hours 53 minutes
\( \overline{\text{2 hours 07 minutes}} \)
Amrita worked for 2 hours and 7 minutes on the other day.
In simple words: To find out how much time Amrita worked on the second day, we subtract the first day's work from the total work. We need to borrow 1 hour and turn it into 60 minutes to do the subtraction properly.

🎯 Exam Tip: When subtracting time, always start with the minutes. If the minutes to be subtracted are more than the minutes available, borrow 1 hour (60 minutes) from the hour column.

Question 8. Rohan takes 25 minutes to write a page. How much time will he require to write 6 pages?
Answer:
Time taken to write 1 page = 25 minutes.
To find the time required to write 6 pages, we multiply the time per page by the number of pages.
Total time \( = 25 \text{ seconds} \times 6 = 150 \) minutes.
Now, we convert 150 minutes into hours and minutes.
We know that 1 hour = 60 minutes.
So, \( \frac{150}{60} \) hours \( = 2 \) with a remainder of \( 30 \).
This means 150 minutes \( = 2 \) hours and 30 minutes.
Therefore, Rohan will require 2 hours and 30 minutes to write 6 pages.
In simple words: First, multiply the time for one page by the total number of pages to get total minutes. Then, divide by 60 to change those minutes into hours and any leftover minutes.

🎯 Exam Tip: After finding the total time in minutes, always convert it to hours and minutes if the number of minutes is 60 or more, as it provides a clearer understanding of the duration.

Question 1. Add 4 hours 30 minutes and 3 hours 15 minutes.
Answer:
To add time, we add minutes with minutes and hours with hours separately.
First, add the minutes:
30 minutes + 15 minutes \( = 45 \) minutes.
Next, add the hours:
4 hours + 3 hours \( = 7 \) hours.
Combining these, the total time is 7 hours and 45 minutes.
In simple words: Add the minutes together, and then add the hours together. If the total minutes are more than 60, convert them into hours and add to the total hours.

🎯 Exam Tip: When adding time, always check if the total minutes are 60 or more. If so, convert every 60 minutes into 1 hour and carry it over to the hour column.

Question 2. Add 7 hours 50 minutes and 5 hours 40 minutes.
Answer:
We add minutes with minutes and hours with hours.
First, add the minutes: 50 minutes + 40 minutes \( = 90 \) minutes.
Next, add the hours: 7 hours + 5 hours \( = 12 \) hours.
So we have 12 hours and 90 minutes.
Since 90 minutes is more than 60 minutes, we convert 90 minutes into hours and minutes. \( 90 \div 60 = 1 \) with a remainder of \( 30 \).
So, 90 minutes \( = 1 \) hour and 30 minutes.
Now, add this 1 hour to the 12 hours: \( 12 + 1 = 13 \) hours.
The total time is 13 hours and 30 minutes.
In simple words: Add the minutes first. If they total more than 60, carry over 1 hour for every 60 minutes. Then add the hours, including any carried-over hours.

🎯 Exam Tip: Always remember to regroup minutes into hours if the total minutes exceed 59. This is a common step in time addition problems.

Question 3. Subtract 11 minutes 24 seconds from 15 minutes 38 seconds.
Answer:
To subtract time, we subtract seconds from seconds and minutes from minutes.
First, subtract the seconds: 38 seconds \( - \) 24 seconds \( = 14 \) seconds.
Next, subtract the minutes: 15 minutes \( - \) 11 minutes \( = 4 \) minutes.
The remaining time is 4 minutes and 14 seconds.
In simple words: Subtract the smaller number of seconds from the larger, then do the same for minutes. Make sure you subtract from the correct total.

🎯 Exam Tip: When subtracting time, always align the units (minutes with minutes, seconds with seconds). If the seconds to be subtracted are larger, remember to borrow 1 minute (60 seconds) from the minutes column.

Question 4. Subtract 1 minute 40 seconds from 3 minutes 10 seconds.
Answer:
We need to subtract 1 minute 40 seconds from 3 minutes 10 seconds.
Since we cannot subtract 40 seconds from 10 seconds, we need to borrow from the minutes.
Borrow 1 minute (which is 60 seconds) from 3 minutes.
So, 3 minutes 10 seconds becomes 2 minutes (3 - 1) and \( 10 + 60 = 70 \) seconds.
Now, we subtract:
2 minutes 70 seconds
\( - \) 1 minute 40 seconds
\( \overline{\text{1 minute 30 seconds}} \)
The difference is 1 minute and 30 seconds.
In simple words: When the seconds part of the top number is smaller, borrow one minute (60 seconds) from the minutes column and add it to the seconds. Then, you can subtract normally.

🎯 Exam Tip: Always show the borrowing step clearly when the seconds or minutes in the subtrahend are larger than those in the minuend. This helps avoid calculation errors.

Question 6. The sports day programme in your school starts at 10:30 in the morning and ends at 4:45 in the evening. Tell, how long did it take in total?
Answer:
First, calculate the duration from the start time to noon:
Start time = 10:30 AM.
Noon = 12:00 PM.
Time from 10:30 AM to 12:00 PM:
12 hours 00 minutes \( = \) 11 hours 60 minutes
\( - \) 10 hours 30 minutes
\( \overline{\text{1 hour 30 minutes}} \)
Next, calculate the duration from noon to the end time:
End time = 4:45 PM.
Time from 12:00 PM to 4:45 PM = 4 hours 45 minutes.
Finally, add these two durations to get the total time:
1 hour 30 minutes
\( + \) 4 hours 45 minutes
\( \overline{\text{5 hours 75 minutes}} \)
Since 75 minutes is more than 60 minutes, convert it:
75 minutes \( = 1 \) hour and 15 minutes.
Add this 1 hour to the 5 hours: \( 5 + 1 = 6 \) hours.
So, the total duration of the sports day programme was 6 hours and 15 minutes.
In simple words: First, find how long it was until noon. Then, find how long it was from noon until the end. Add these two times together, and if minutes go over 60, change them into hours.

🎯 Exam Tip: When calculating durations that cross noon or midnight, it's often helpful to break the problem into two parts: before the hour mark and after, then add the segments.

Question 7. Naina goes to bed (sleeps) at 9:30 at night and wakes up at 6:20 in the morning. How long did she sleep in total?
Answer:
First, calculate the time Naina slept from 9:30 PM until midnight (12:00 AM):
12 hours 00 minutes \( = \) 11 hours 60 minutes
\( - \) 09 hours 30 minutes
\( \overline{\text{2 hours 30 minutes}} \)
Next, calculate the time she slept from midnight (12:00 AM) until she woke up at 6:20 AM:
Time from 12:00 AM to 6:20 AM = 6 hours 20 minutes.
Finally, add these two durations to find her total sleep time:
2 hours 30 minutes
\( + \) 6 hours 20 minutes
\( \overline{\text{8 hours 50 minutes}} \)
Naina slept for a total of 8 hours and 50 minutes.
In simple words: To find the total sleep time, first calculate how long she slept before midnight, then how long she slept after midnight until morning, and add those two times together.

🎯 Exam Tip: For problems spanning across midnight, it's easiest to break the time into two segments: before midnight and after midnight, then sum them up.

Question 8. If it takes 30 seconds to make one brick, how long will it take to make 8 bricks?
Answer:
Time taken to make 1 brick = 30 seconds.
To find the time taken to make 8 bricks, we multiply the time for one brick by the number of bricks.
Total time \( = 30 \text{ seconds} \times 8 = 240 \) seconds.
Now, we convert 240 seconds into minutes.
We know that 1 minute = 60 seconds.
So, \( \frac{240}{60} \) minutes \( = 4 \) minutes.
Therefore, it will take 4 minutes to make 8 bricks.
In simple words: Multiply the time for one brick by the total number of bricks to get the total seconds. Then, divide by 60 to change the seconds into minutes.

🎯 Exam Tip: Always convert seconds to minutes if the total seconds are 60 or more. This makes the answer easier to understand and usually expected in such problems.

Question 9. If it takes 15 minutes to water one seed plot in a field, how long will it take to water 5 such seed plots?
Answer:
Time taken to water one seed plot = 15 minutes.
To find the time taken for 5 seed plots, we multiply the time for one plot by the number of plots.
Total time \( = 15 \text{ minutes} \times 5 = 75 \) minutes.
Now, we convert 75 minutes into hours and minutes.
We know that 1 hour = 60 minutes.
So, 75 minutes \( = 1 \) hour and 15 minutes (since \( 75 - 60 = 15 \)).
Therefore, it will take 1 hour and 15 minutes to water 5 seed plots.
In simple words: Multiply the time for one plot by 5 to get the total minutes. Then, change any minutes over 60 into hours and leftover minutes.

🎯 Exam Tip: Similar to other time problems, remember to convert minutes into hours and minutes if the total minutes are 60 or more. This makes the answer complete and easy to read.