Quantitative Aptitude - Arithmetic Ability Questions

What is the mean of first hundred natural numbers?

Two pipes P and Q can fill an empty tank in 25 hours and 20 hours respectively. Pipe R alone can empty the completely filled tank in 50 hours. Firstly both the pipes P and Q are opened and after 8 hours pipe R is also opened. What will be the total time (in hours) taken to completely fill the tank?

A tap can fill a tank in 20 minutes. If a leakage is capable of emptying the tank in 60 minutes, the tank will be filled in

What is the circumference (in cm) of a circle whose area is 616 sq cm?

Which of the following is correct?

If x = 5 + 15 - 1 & y = 5 - 15 + 1, then find the value of x2 - y2.

Coefficient of x in (x + 11)(3 -­ 5x) is _____.

What is the value of ( 1/√3 + cot60) ?