Quantitative Aptitude - Arithmetic Ability Questions

If cos3A = X, then value of X?

If 2x-12x = 5, then what is the value x2 + 116x2 - 2

The average of 8 consecutive natural numbers is 38.5. What is the largest of these 8 numbers?

Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 16000 for 2 years at 10% per annum. The sum placed on simple interest is:

In a ∆ABC, BC is extended upto D, ∡ACD =120°, ∡B = 1/2 A. Then ∡A is

A cuboid of size 50 cm × 40 cm × 30 cm is cut into 8 identical parts by 3 cuts. What is the total surface area (in cm2) of all the 8 parts?

The simplest form of 3565/1495 is

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