Quantitative Aptitude - Arithmetic Ability Questions

Which of the following is correct?

If x = (a/b) + (b/a), y = (b/c) + (c/b) and z = (c/a) + (a/c), then what is the value of xyz – x2 – y2 – z2?

If tanA = x, then x is

Find the perimeter (in cm) of a semicircle of radius 14 cm.

One pipe can fill an empty cistern in 4 hours while another can drain the cistern when full in 10 hours. Both the pipes were turned on when the cistern was half-empty. How long will it take for the cistern to be full?

Ram is thrice as fast as Mohan and Nohan is twice as fast as Sohan. The distance covered by Sohan in 42 minutes will be covered by Mohan in

A and B can do a piece of work in 72 days. B and C can do it in 120 days and A and C can do it in 90 days. A alone can do it in:

The largest chord of the circle has a length of 20.4 cm. The radius of the circle will be_____.