Let the number be 10x + y.∴ 10x + y - (10y + x) = 27or 9x - 9y = 27∴ x - y = 3 .......(I)x + y = 13 .......(II)From eqn (I) and (II)x = 8 and y = 5.So the number = 85Therefore, product = 8 x 5 = 40
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