Question

A bag contains 5 red balls and some blue balls. If the probabil
drawing a blue ball from the bag is thrice that of a red ball, find
number of blue balls in the bag.
CBSE​

Answer 1

P(red ball) x3= P(blue ball)
=No of red ball/total balls x3= no of blue balls/total balls
(Total balls from LHS and RHS gets Cancelled )

Red balls x3= blue balls

5x3= blue balls

Therefore there are 15 blue balls

Answer 2

Step-by-step explanation:

No of red balls = 5

no of blue balls be = x

probability of drawing blue ball is x / 5 + x

probability of drawing red balls is 5 / 5 + x

x / 5 + x = 3 × 5 / 5 +×

so x = 10