## EXERCISE 3.4

#### Page No 76:

#### Question 1:

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 will be a cloudy day.

#### Answer:

(i) Certain

(ii) Can happen but not certain

- Impossible as there are only six faces on a dice marked as 1, 2, 3, 4, 5, 6 on it.

(iv) Can happen but not certain

(v) Can happen but not certain

#### 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:

(i) Probability =

P (appearance of 2) =

(ii) P (appearance of 5) =

#### 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 has two faces − Head and Tail. One team can opt either Head or Tail.

Probability =

Probability (our team starts first) =

#### Question 4:

A box contains pairs of socks of two colours (black and white). I have picked out a white sock. I pick out one more with my eyes closed. What is the probability that it will make a pair?

#### Answer:

It can be observed that while closing the eyes, one can draw either a black sock or a white sock. Therefore, there are two possible cases.

Probability =

Probability (a pair of white socks will be formed) =