A bag contains 5 red balls and 'n' green balls. If the P(green ball) = 3 X P(red ball), then what is the value of n?

Dear Student,

Given : A bag contains 5 red balls and ' n ' green balls.

We know Probability P ( E ) =

So,
Total number of events n ( S ) = Total number of balls  =  5 + n

Then

Probability of getting a red ball =  P ( Red ball ) =

And

Probability of getting a green ball =  P ( Green ball ) =

Given  : P ( Green ball ) =  3 $×$ P ( Red ball )

= 3 $×$

n  =  15                                                                                  ( Ans )