Quantitative Aptitude - Arithmetic Ability Questions

sec2Acosec2A is equal to

If sin(A/2) = x, then the value of x is

If x2+y2+z2-8x+6y-4z+29 = 0, then find the value of z(x+y).

The value of 1/64 is equal to square of

Two numbers are 50% and 90% lesser than a third number. By how much percent is the second number to be enhanced to make it equal to the first number?

If 2x+29x = 4, then the value of 27x3+127x3

If x = [1/(√5 + √3)], y = [1/(√7 + √5)] and z = [1/(√7 + √3)], then what is the value of (x + y + z)?

A car travels a certain distance at 32 km/h and comes back at 68 km/h. What is the average speed for total journey?