Quantitative Aptitude - Arithmetic Ability Questions

If cos -4π/3 = x, then the value of x is

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

In ΔDEF measure of angle E is 90 deg. If cotD = 8/15, and DE = 16cm, then what is the length (in cm) of side EF?

Rahul can complete a work in 18 days and Sonu can complete the same work in 15 days. If both together work for 5 days, then what part of total work is left?

Fraction that lies between 2/5 and 4/9 is

G is the centroid of the equilateral triangle ABC, if AB = 9cm then AG is equal to

The ratio of present ages of Rangitha and Shaheen is 6:5. After 12 years the ratio of their ages will be 7:6. What is Rangitha's present age?

A and B undertake a piece of work for Rs. 250 . A alone can do that work in 5 days and B alone can do that work in 15 days . With the help of C, they finish the work in 3 days . If every one gets paid in proportion to work done by them, the amount C will get is