Question

A box contains 100 red cards, 200 yellow cards and 50 blue cards. If a card is drawn at random from the box, then find the probability that it will be (i) a blue card (ii) not a yellow card (iii) neither yellow nor a blue card.

Answer 1

Number of red cards = 100

Number of yellow cards = 200

Number of blue cards = 50

Total number of cards = 100 + 200 + 50 = 350

(i) 

`P(\text{a blue card})=(\text{Number of blue card})/(\text{Total number of card})`

`=50/350`

`=1/7`

(iii)

`P(\text{Neither yellow nor a blue card})=(\text{Number of cards which are neither yellow nor blue})/(\text{Total number of cards})`

`=(\text{Number of red cards})/(\text{Total number of cards})`

`=100/350`

`=2/7`