Number System
In a five-litre mixture of milk and water the portion of water is 30%. How much milk should be added to the mixture so that the portion of water reduces to 5% ?
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
Let the number of children be 'x' Therefore, each child will receiveX x 60/100 = 3x/5 chocolates∴ X x 3x/5 = 735∴ x² x 735x5/3 = 1225∴ x = 1225 = 35∴ Number of chocolates = 3x/5 = 21
Let the number be 10x + y.Therefore, x + y = 9 ..................(i)10x + y - (10y + x) = 4510x + y - 10y - x = 45Therefore, x - y = 5 ..................(ii)From (i) and (ii), x = 7, y = 2Number = 72Therefore, = x x y = 7 x 2 = 14
EXAMIANS