Quantitative Aptitude - Arithmetic Ability Questions

Two pipes fill a tank when working individually in 25 and 40 hours, respectively while a third pipe can drain the filled tank in 16 hours. If all the three pipes are turned on at the same time when the tank is empty, how long will it take to fill the tank completely ?

A solid sphere and a solid hemisphere have the same total surface area. The ratio of their volumes is (Take, π=22/7)

Select the odd word/letters/number/number pair from the given alternatives.

Given: 5x -3(2x-7) > 3x - 1 < 7 + 4x; then x can take which of the following values?

The value of (1 - √2) + (√2 - √3) + (√3 - √4) + ..... + (√15 - √16) is

Expand and simplify (x + 5)2 + (x - 3)2

20 is 0.25% of?

Reflection of the point (3,-6) in the y-axis is