Number System
An urn contains 9 blue, 7 white and 4 black balls. If 2 balls are drawn at random, then what is the probability that only one ball is white ?
Original mixture = 5 litre; Milk = 3.5 litre;Water = 1.5 litre Let x litre of milk be added so thatthe mixture becomes (x + 5) litres and the percentage of water becomes 5%So, 1.5 = (x + 5) x 5/10030 = x + 5∴ x = 25 litre
EXAMIANS