Question

a bag contain 15 white and some black balls. if the probability of drawing a black ball from the bag is thrice that of drawing a white ball,find the number of black balls in the bag​

Answer 1

Answer:

Step-by-step explanation:

Let the number of black balls be x

Total no of balls =15+x

Given probability of drawing black ball is thrice that of drawing a white ball

So,

probability of drawing white ball=15/15+x

Probability of drawing a black ball is x/x+15

x/x+15=3(15/x+15)

x/x+15=45/x+15

X=45

Answer 2

so, there are 45 black balls..

hope it helped .