To x litres of an x% solution of acid, y litres of water is added to get (x –10)% solution of acid. If x > 20, then value of y is
A] x2 /100
D] 10x2 /x-10
A grocer purchased 2 kg. of rice at the rate of Rs.15 per kg. and 3 kg. of rice at the rate of Rs.13 per kg. At what price per kg. should he sell the mixture to earn profit on the cost price?
In 1 kg mixture of sand and iron, 20% is iron. How much sand should be addd, so that the proportion of iron becomes 5%?
A] 3 kg
B] 4 kg
C] 5 kg
D] 6 kg
In a mixture of milk and water the proportion of water by weight was 75%. If in the 60 gms mixture 15 gms, water was added, what would be the percentage of water in the new mixture?
A and B are two alloys of gold and copper prepared by missing metals in the ratio 7: 2 and 7: 11 respectively. If equal quantities of the alloys are melted to form a third alloy C, the ratio of gold and copper in C will be:
A] 5: 7
B] 5: 9
C] 7: 5