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

Total number of possible outcomes, n(S) = 100 + 200 + 50 = 350 

(i) Number of favorable outcomes, 

n(E) = 50

∴ P(E) = \(\frac{n(E)}{n(S)}\) = \(\frac{1}{7}\)

(ii) Number of favorable outcomes, n(E) = 100 + 50 = 150

∴ P(E) = \(\frac{n(E)}{n(S)}\) = \(\frac{3}{7}\)

(iii) Number of favorable outcomes, 

n(E) = 100

∴ P(E) = \(\frac{n(E)}{n(S)}\) = \(\frac{2}{7}\)