Quantitative Aptitude - Arithmetic Ability Questions

Coefficient of x in (x + 8)(6 -­ 3x) is

An equilateral triangle of area 300 cm2 is cut from its three vertices to form a regular hexagon. Area of hexagon is what percent of the area of triangle?

What will be the value of xy, if x2+y2 = 45 and x-y=5 ?

The sum of the digits of a 2-digit number is 8. If we add 36 to the number, the new number obtained is a number formed by interchange of the digits. What is the number?

Two valves P and B can fill a sump in 37.5 minutes and 45 minutes respectively. Both valves are opened. The sump will be filled in just 30 minutes, if valve B is turned off after

If 2x- ­2(x ­- 2) < 5 ­- x > ­-2x + 2; then the value of x is

If 2cos2A - 1 = x, then the value of x is

What is the value of [(cos 3θ + 2cos 5θ + cos 7θ)÷(cos θ + 2cos 3θ + cos 5θ)] + sin 2θ tan 3θ?