NCERT Solution class 7 Mathematics EXERCISE- 3.4

CHAPTER – 3

Q1. Tell whether the following is certain to happen, impossible, 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 is a cloudy day.

SOLUTION:-

(i) It is certain to happen.

(ii) It can happen but not certain.

(iii) It is impossible . Because there are only six faces on a die is marked as 1,2,3,4,5 and 6 on it.

(iv) It can happen but not certain.

(v) It can happen but not certain.

Q2. There are 6 marbles in box with numbers from 1 to 6 marked on each of them.

(i) What is the probability of drawings marbles with number 2 ?

(ii) what is the probability of drawings a marble with number 5 ?

SOLUTION:-

(i) From the question, it is given that

There are 6 marbles in the box with numbers from 1 to 6 are marked.

Probability of drawings a marble with number 2 = Numbers of favourable outcomes/No of possible outcomes/

Number of possible outcomes = (1/6)

(ii) From the question, It is given that

There are 6 marbles in the box with numbers from 1 to 6 are marked.

Probability of drawing a marble with number 5 = Number of favourable outcomes/

Number of possible outcomes = (1/6)

Q3. A coin is flipped to decide which team starts the game. What is the probability that your team will start?

SOLUTION:-

A coin has two faces one is head and other is Tail.

Now, one team can choose either Head or Tail.

Probability of our team starts first= Number of favourable outcomes / Numbers of possible outcomes

= ½