Question

A bag contains 5 red balls and some blue balls. The probability of taking out a blue ball is 3 times that of a red ball. Find the number of blue balls

Answer 1

let the no. of blue balls be 'X'

no. of Reb ball is 5

total balls is 5+x

according. to the question:

x/5+x=3( 5/5+x)

x/5+x= 15/5+x

( as both the denominators are common we cut it)

x=15

The no. of blue balls is 15