Quantitative Aptitude - Arithmetic Ability Questions

What is the difference of the factors of the expression x2 + (1/x2) – 6?

The sum of three consecutive even numbers is 42. Find the middle number.

P and Q together can make a door in 12 days. They started the work together but after 8 days P left the work. The remaining work is completed by Q alone in 7 more days. In how many days can P alone complete the entire work?

Δ DEF is right angled at E. If m∠F = 45°, then what is the value of 2 Sin F x Cot F?

The point R(a,b) is first reflected in origin to R1 and R1 is reflected in x-axis to (-3,4). The co-ordinates of point R are

The standard deviation of the set {10, 11, 12, 9, 8} is

What should be added to 8(3x - ­4y) to obtain 18x ­- 18y?

What is the ratio of radius of incircle and circumcircle for an equilateral triangle with an area of 22√3 sq. units?