Question

A bag contains $$3$$ red balls, $$4$$ blue balls and $$1$$ yellow ball, all the balls being identical in shape and size. If a ball is taken out of the bag without looking into it; find the probability that the ball is neither yellow nor red.

Answer 1

The total number of balls in the bag $$= 3 + 4 + 1 = 8$$ balls

So, the number of possible outcomes $$= 8 = n(S)$$

Neither yellow ball nor red ball means a blue ball

Event of not drawing a yellow or red ball $$= E = 4$$

So, $$n(E) = 4$$

Thus, probability of not drawing a yellow or red ball $$= n(E)/ n(S) = 4/8 = 1/2$$