GSEB Class 7 Maths Solutions Chapter 3 Data Handling Exercise 3.4

Question 1. Tell whether the following is certain to happen, impossible, or can happen but not certain.
(i) You are older today than yesterday.
(ii) A tossed coin will land heads up.
(iii) A die when tossed shall land up with 8 on top.
(iv) The next traffic light seen will be green
(v) Tomorrow will be a cloudy day.
Answer:

Exam Tip: Understand the difference between 'certain', 'impossible', and 'possible but not certain' to correctly classify everyday events.

Question 2. There are 6 marbles in a box with numbers from 1 to 6 marked on each of them.
(i) What is the probability of drawing a marble with number 2?
(ii) What is the probability of drawing a marble with number 5?
Answer: There are 6 marbles in a container, each bearing a unique number from 1 to 6. Consequently, the total amount of marbles is 6, which represents the total number of possible results when selecting one marble.
(i) The chance of getting a marble with the number 2 is \( \frac { 1 }{ 6 } \), because there is only one marble with the number 2 on it among the six.
(ii) The chance of getting a marble with the number 5 is also \( \frac { 1 }{ 6 } \), as there is only one marble with the number 5 on it among the six.
In simple words: With 6 marbles, each numbered 1 to 6, the chance of picking any particular numbered marble (like 2 or 5) is 1 out of 6, since each number appears only once.

Exam Tip: In probability, the number of favorable outcomes is divided by the total number of possible outcomes. For unique items, each has an equal chance.

Question 3. A coin is flipped to decide which team starts the game. What is the probability that your team will start?
Answer: A coin possesses two sides, a head (H) and a tail (T). When a coin is tossed, it lands showing either a 'H' or a 'T'. Therefore, there are two potential outcomes. The number of favorable outcomes for your team to begin the game is 1 (either getting a head or a tail, depending on your team's choice). Hence, the likelihood of your team starting the game is \( \frac { 1 }{ 2 } \).
In simple words: When you flip a coin, there are two possible outcomes: heads or tails. Since your team can choose one, you have a 1 in 2 chance, so the probability is \( \frac { 1 }{ 2 } \).

Exam Tip: Remember that a fair coin always gives an equal probability of 1/2 for heads and 1/2 for tails, making decisions fair.