A bag contains 3 red balls, 5 yellow balls and 7 pink balls. If one ball is drawn at random from the bag, what is the probability that it is either pink or red?

A 2/3

B 1/8

C 3/8

D 3/4

Correct Answer: Option A

Given number of balls = 3 + 5 + 7 = 15

One ball is drawn randomly = 15C1

probability that it is either pink or red

= \(\frac{7{\mathrm C}_1\;+\;3{\mathrm C}_1}{15{\mathrm C}_1}\;=\;\frac{7\;+\;3}{15}\;=\;\frac{10}{15}\;=\;\frac23\)