A scientist mixes 10% water in his solution but he is not content with it so he again mixes 10% more water in the previous mixture. What is the profit percentage of the scientist if he sells it at cost price:

Direction : What should come in place of the question (?) in the following question.

(?)² + (65)²=(160)² -  (90)² – 7191

If each edge of a cube is reduced by 25 percent, find the ratio of the volume of the original cube and the resulting cube?

The simple interest accrued on an amount of Rs. 8500 at the end of four years is Rs.3400. What would be the compound interest accrued on the same amount at the same rate of interest after three years?

A boat goes 12 km downstream and comes back to the starting point in 3 hours. If the speed of the current is 3 km/hr, then the speed (in km/hr) of the boat in still water is : 

In how much time the money of Rs 6400 will be Rs 6561 at the rate of 5 percent annual interest if the compound interest is payable quarterly?

When a number is increased by 24, it becomes 115% of itself. What is the number?

A policeman starts to chase a thief. When the thief goes 10 steps the policeman moves 8 steps and 5 steps of the policeman are equal to 7 steps of the thief. The ratio of the speeds of the policeman and the thief is: