question_answer

A box contains 5 green balls and some white balls. If the probability of drawing a white ball is half of the probability of drawing a green ball, then find the number of white balls in the box.

A)  10                               

B)  5                    

C)  15                               

D)  20                   

Correct Answer: A

Solution :

Let number of white balls be Total number of balls in the box Probability of drawing a white ball Probability of drawing a green ball According to question,