Question

A bag contains 15 white and some black balls if the probability of drawing a black ball from the back is thrice that of drawing a white wall find the number of black balls in the bag

Answer 1

Here,

No. of white balls = 15

Let, the no. of black balls be 'x'

Then, total no. of balls = 15 + x

Now,

P(drawing a white ball) = 15/(15 + x)

And, P(drawing a black ball) = x/(15 + x)

But A/Q,

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

=> x = 3*15

=> x = 45

Therefore, there are 45 black balls in the bag.

: )

Answer 2

Answer:

Step-by-step explanation: