Question

A box contains 3 black balls, 4 red balls and 3 green balls. All the balls are identical in shape and size. Rohit takes out a ball from the bag without looking into it. What is the probability that the ball drawn is a black or green ball?

• A. $\frac{3}{10}$
• B. $\frac{4}{10}$
• C. $\frac{3}{5}$
• D. $\frac{1}{2}$

Answer 1

The correct option is C

$\frac{3}{5}$

Given,

Number of black balls in the bag = 3

Number of red balls in the bag = 4

Number of green balls in the bag = 3

Total number of balls in the bag = 3 + 4 + 3 = 10

Number of favourable outcomes = Number of black balls in the bag + Number of green balls in the bag

= 3 + 3

= 6

$\text{Probability of drawing a black or green ball}=\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$

= $\frac{6}{10}$

= $\frac{3}{5}$

$\therefore$ Probability of drawing a black or green ball = $\frac{3}{5}$