Question

ucsda 2. A bag contains 30 balls out of which x are black. If 10 more black balls are put in the box. The probability of drawing a black ball is double of what it was before ​

Answer 1

Step-by-step explanation:

Total balls = 30

Black ball = x

Probability of black balss = x/30

10 balls more added -

Total balls = 30+10= 40

ATQ---

x+10/40 = 2(x/30)

30(x+10) = 80x

30x + 300 = 80x

300 = 80x-30x

300 = 50x

300/50 = x

x = 6

Black balls = 6