Quantitative Aptitude - Arithmetic Ability Questions

If cot(A/2) = x, then x is equal to

If secA -­ tanA = x, then the value of x is

If  tan2A / (secA -­ 1)2 = x, then the value of x is

In ΔXYZ measure of angle Y is 90 deg. If cot X = 5/12, and XY = 2.5 cm, then what is the length (in cm) of side XZ?

If ab+ba = -1, then the value of a2b-b2a is

The area of a semicircle is 308 sq.cm. Calculate its perimeter (in cm)

10 persons can do a job in X days. If 20 persons with twice the efficiency can do the same job in 5 days, then find the value of X?

A mixture of 50 kg of cement and gravel contains 10% of gravel. How many kg of gravel must be added to make the gravel content 28% in the new mixture?