When the price of an audio system was reduced by 20%, the sale increased by 80%. What was the net effect on the sale?

If A’s income is 40 % less than that of B, how much percent B's income is more than that of A? 

The length of a rectangle is increased by 60% then by how much % should the breadth be reduced so that its area does not change?

The number obtained by subtracting two-third of 75% of 600 from a number is 320, what is the original number?

A seller uses 920 gm in place of one kg to sell his goods. When he sells his articles at 15% gain on cost price, the actual percentage of profit is :

If "basis points" are defined so that 1 percent is equal to 100 basis points, then by how many basis points is 82.5 percent greater than 62.5 percent. 

A basket contains 300 mangoes. 75 Mangoes were distributed among some student. Find the percentage of mangoes left in the basket.

Deepak starts the month of February with provisions expected to last for the entire month. After few days, he find that the provisions will be short by 10 days and it is calculated that if the provisions left is immediately tripled, it will complete the shortfall. If the provisions left is doubled instead of being tripled, and simultaneously the diet of the Deepak is decreased by 20%, then the provisions will fall short by-