Real Numbers

Question

A box contains 12 balls out of which x are black. If one ball is drawn at randone from the box, what is the probability that it will be a black ball.

If 6 more black balls are put in the box, the probability of drawing a black ball is now double of what it was before. Find x

Solution

Solution not provided.
Ans. $2 over 12 comma space space space x space equals space 3$

Tips: -

Problems Based on Balls