Quantitative Aptitude - Arithmetic Ability Questions

If 6 years are subtracted from the present age of Ayush and takes 25% of that then we get the present age of his only son. 4 years ago, his daughter’s age is 7 years more than his son. Sum of daughter’s present age and his wife’s present age is 10 years more than Ayush’s present age then find the present age of Ayush if average of present age of entire family is 30.25 yr? 

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?

If a boat goes upstream at a speed of 18 km/hr and comes back the same distance at 30 km/hr. What is the average speed (in km/hr) for the total journey?

When a discount of 20% is given on a pizza, the profit is 32%. If the discount is 18%, then the profit is

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)?

Mishti's birthday is on Thursday 27th April. On what day of the week will be Aradhya's Birthday in the same year, if Aradhya was born on 20th October?

I gain 19% if I sell an article for Rs. 595. What would be my gain or loss percentage if I sell it for Rs. 475?

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?