RBSE Solutions Class 5 Maths Chapter 11 Time More Ques

Question 1. (i) Convert the following hours into minutes
1. \(1\frac{1}{4}\) hour = \(\_\_\) minutes
Answer: To convert \(1\frac{1}{4}\) hours into minutes, we first separate the whole hours from the fraction. One hour equals 60 minutes, and one-fourth of an hour is \( \frac{1}{4} \times 60 \) minutes.
\( 1\frac {1}{4} \text{ hour} = 1 \text{ hour} + \frac {1}{4} \text{ hour} \)
\( = (1 \times 60) \text{ minutes} + (\frac {1}{4} \times 60) \text{ minutes} \)
\( = 60 \text{ minutes} + 15 \text{ minutes} \)
\( = 75 \text{ minutes} \)
In simple words: To change mixed hours into minutes, first change the whole hours, then change the fraction of an hour, and add them together. One hour is always 60 minutes.

🎯 Exam Tip: Remember that a mixed number like \(1\frac{1}{4}\) means 1 whole unit plus a fractional part. Treat each part separately for conversion and then sum them up.

Question 1. (i) 2. \(2\frac{1}{2}\) hour = \(\_\_\) minutes
Answer: We need to convert \(2\frac{1}{2}\) hours to minutes. We know that 1 hour is 60 minutes.
\( 2\frac {1}{2} \text{ hour} = 2 \text{ hours} + \frac {1}{2} \text{ hour} \)
\( = (2 \times 60) \text{ minutes} + (\frac {1}{2} \times 60) \text{ minutes} \)
\( = 120 \text{ minutes} + 30 \text{ minutes} \)
\( = 150 \text{ minutes} \)
In simple words: To find out how many minutes are in two and a half hours, multiply the whole hours by 60, then multiply the half hour by 60, and add the two results.

🎯 Exam Tip: Always show your calculation steps clearly, especially when converting mixed units. This helps avoid mistakes and makes your work easy to understand.

Question 1. (i) 3. \(5\frac{3}{4}\) hour = \(\_\_\) minutes
Answer: To convert \(5\frac{3}{4}\) hours into minutes, we will separate the whole hours and the fraction, then convert each part.
\( 5\frac {3}{4} \text{ hour} = 5 \text{ hours} + \frac {3}{4} \text{ hour} \)
\( = (5 \times 60) \text{ minutes} + (\frac {3}{4} \times 60) \text{ minutes} \)
\( = 300 \text{ minutes} + (3 \times 15) \text{ minutes} \)
\( = 300 \text{ minutes} + 45 \text{ minutes} \)
\( = 345 \text{ minutes} \)
In simple words: First, turn 5 hours into minutes by multiplying by 60. Then, turn three-quarters of an hour into minutes. Add both numbers to get the total minutes.

🎯 Exam Tip: When multiplying fractions like \( \frac{3}{4} \) by a whole number, you can divide the whole number by the denominator first, then multiply by the numerator. For instance, \( \frac{3}{4} \times 60 = 3 \times (60 \div 4) = 3 \times 15 \).

Question 1. (i) 4. \(3\frac{1}{5}\) hour = \(\_\_\) minutes
Answer: We need to convert \(3\frac{1}{5}\) hours into minutes. We know there are 60 minutes in an hour.
\( 3\frac {1}{5} \text{ hour} = 3 \text{ hours} + \frac {1}{5} \text{ hour} \)
\( = (3 \times 60) \text{ minutes} + (\frac {1}{5} \times 60) \text{ minutes} \)
\( = 180 \text{ minutes} + 12 \text{ minutes} \)
\( = 192 \text{ minutes} \)
In simple words: To change three and one-fifth hours into minutes, multiply the 3 hours by 60, then multiply the \( \frac{1}{5} \) hour by 60, and finally add them up.

🎯 Exam Tip: Practice your multiplication tables for 60 to quickly convert between hours and minutes without errors.

Question 2. Convert the time units of following questions,
1. 20 minutes = \(\_\_\) seconds
Answer: To convert minutes into seconds, we use the fact that 1 minute equals 60 seconds.
\( 20 \text{ minutes} = 20 \times 60 \text{ seconds} \)
\( = 1200 \text{ seconds} \)
In simple words: To change minutes into seconds, multiply the number of minutes by 60.

🎯 Exam Tip: Always remember the basic time conversion facts: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day. These are fundamental for solving such problems.

Question 2. 2. \(6\frac{1}{2}\) minutes = \(\_\_\) seconds
Answer: To convert \(6\frac{1}{2}\) minutes into seconds, we convert the whole minutes and the fractional part separately.
\( 6\frac {1}{2} \text{ minutes} = 6 \text{ minutes} + \frac {1}{2} \text{ minute} \)
\( = (6 \times 60) \text{ seconds} + (\frac {1}{2} \times 60) \text{ seconds} \)
\( = 360 \text{ seconds} + 30 \text{ seconds} \)
\( = 390 \text{ seconds} \)
In simple words: First, change the 6 full minutes to seconds. Then, change the half minute to seconds. Finally, add these two numbers together.

🎯 Exam Tip: Clearly write down each step of the conversion. This helps to break down complex problems into simpler, manageable parts.

Question 2. 3. \(15\frac{1}{4}\) minutes = \(\_\_\) seconds
Answer: We need to convert \(15\frac{1}{4}\) minutes into seconds. Each minute has 60 seconds.
\( 15\frac {1}{4} \text{ minutes} = 15 \text{ minutes} + \frac {1}{4} \text{ minute} \)
\( = (15 \times 60) \text{ seconds} + (\frac {1}{4} \times 60) \text{ seconds} \)
\( = 900 \text{ seconds} + 15 \text{ seconds} \)
\( = 915 \text{ seconds} \)
In simple words: First, turn 15 minutes into seconds. Then, turn one-quarter of a minute into seconds. Add them up to get the total seconds.

🎯 Exam Tip: Pay attention to the units in the question and in your answer to ensure they match and you've performed the correct conversion. Double-check your multiplication.

Question 2. 4. 4 hour = \(\_\_\) seconds
Answer: To convert 4 hours into seconds, we first convert hours to minutes and then minutes to seconds.
\( 4 \text{ hours} = 4 \times 60 \text{ minutes} \)
\( = 240 \text{ minutes} \)
Now, convert minutes to seconds:
\( 240 \text{ minutes} = 240 \times 60 \text{ seconds} \)
\( = 14400 \text{ seconds} \)
In simple words: First, change 4 hours into minutes by multiplying by 60. Then, change those minutes into seconds by multiplying by 60 again.

🎯 Exam Tip: For conversions involving multiple steps (like hours to seconds), it's best to do it step-by-step (hours to minutes, then minutes to seconds) to reduce calculation errors.

Question 2. 5. Convert \(2\frac{3}{4}\) hour to seconds
Answer: We need to convert \(2\frac{3}{4}\) hours into seconds. This involves two steps: converting hours to minutes, and then minutes to seconds.
\( 2\frac {3}{4} \text{ hour} = 2 \text{ hours} + \frac {3}{4} \text{ hour} \)
First, convert to minutes:
\( = (2 \times 60) \text{ minutes} + (\frac {3}{4} \times 60) \text{ minutes} \)
\( = 120 \text{ minutes} + (3 \times 15) \text{ minutes} \)
\( = 120 \text{ minutes} + 45 \text{ minutes} \)
\( = 165 \text{ minutes} \)
Now, convert minutes to seconds:
\( 165 \text{ minutes} = 165 \times 60 \text{ seconds} \)
\( = 9900 \text{ seconds} \)
In simple words: First, figure out how many minutes are in \(2\frac{3}{4}\) hours. Then, take that total number of minutes and multiply it by 60 to find the total seconds.

🎯 Exam Tip: When dealing with mixed numbers in multi-step conversions, always convert the entire mixed number to a single unit (e.g., all minutes) before proceeding to the next unit (e.g., seconds).