Question

A box contains loo 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

Total no. of possible outcomes = 100 + 200 + 50 = 350 {100 red, 200 yellow & 50 blue}

(i) E ⟶ event of getting blue card.

No. of favourable outcomes = 50 {50 blue cards}

P(E) = 50/350 = 1/7

(ii) E ⟶ event of getting yellow card

No. of favourable outcomes = 200 {200 yellow}

P(E) = 200/350 = 4/7

Bar E⟶ event of not getting yellow card

P(Bar E)=1−P(E)

= 1−4/7 = 3/7

(iii) E ⟶ getting neither yellow nor a blue card

No. of favourable outcomes = 350 – 200 – 50 = 100 {removing 200 yellow & 50 blue cards}

P(E) = 100/350 = 2/7