In a bag,there are 18 cards of which x cards are coloured and the rest are white.When another 6 white cards are added into the bag,the probability of a white card being picked is x over 8.Find the value of x.

Answer:6

How?

1 answer

now: x and 18-x
after 6 more whites: x and 24-x

(24-x)/24 = x/8
8(24-x) = 24x
192-8x = 24x
32x = 192
x = 6