Question

If a bag contains 10 white balls and X back balls . if the probability of drawing a black ball is double that of a white ball the number of black balls are

Answer 1

Answer:

Step-by-step explanation:

p(black balls) = 2(P(white balls))

now P(black balls) = x/10+x

now P(white balls) = 10/10+x

now x/10+x = 2(10/10+x)

= x = 20

the number of black balls is 20

Answer 2

Answer:

20

Step-by-step explanation:

probability of white ball is 10/10+x

probability of black ball is twice the probability of white ball so 20/10+x

sum of probabilities is 1

30/10+x is 1

30 = 10+ x

x = 20