Quantitative Aptitude - Arithmetic Ability Questions

Kanchan bought a clock with 25% discount on marked price. She sold it with 75% gain on the price she bought. What was her profit percentage on the marked price?

Seven years from now Virat will be twice as old as Mohinder. Five years ago Mohinder's age was one year less than 2/5 of Virat's age. What is Virat's present age?

A shopkeeper offers the following 3 schemes. Which scheme has the lowest discount percentage (all articles have same marked price)?

I. Two successive discounts of 10% and 10%

II. Buy 7 get 8

III. Buy 9 get 1 free

Priya’s age was cube of an integral number (different from 1) four years ago and square of an integral number after four years. How long should she wait so that her age becomes square of a number in the previous year and cube of a number in the next year?

There are five boxes in a cargo hold. The weight of the first box is 200 kg and the weight of the second box is 20% higher than the weight of the third box, whose weight is 25% higher than the first box’s weight. The fourth box at 350 kg is 30% lighter than the fifth box. Find the difference in the average weight of the four heaviest boxes and the four lightest boxes.

Albert invested an amount of x rupees in a fixed deposit scheme offering 10% per annum for 1st year and 15% per annum for 2nd year and received an amount of Rs 20,240 after the two years. What is x (in Rs)?

In a computer game, there are builders and destroyers. Together there are 20 of them. Some of them try to build a wall around a castle while the rest try to demolish it. Each of the builders can build the wall alone in 15 hours while any of the destroyers can demolish it in 10 hours. If all 20 builders and destroyers are made active when there is no wall and the wall gets built in 3 hours, how many of them are destroyers?

A student multiplied a number by 4/5 instead of 5/4. What is the percentage error in the calculation?