Quantitative Aptitude - Arithmetic Ability Questions

What is the average of all natural numbers from 21 to 39?

If x -­ y = 7 and xy = 32, then value of (x2 + y2) is

If 4x - 7y = 3 and 2x - y = 9, then x - y is.

The length and breadth of a rectangle is in the ratio of 3 : 1. If its perimeter is 96 m, then what is the length of the rectangle?

∆ABC is right angled at B. If m∠A = 45°, then find the value of (coseC + 1/√3).

Select the odd word/letters/number/number pair from the given alternatives.

A and B are 15 kms apart and when travelling towards each other meet after half an hour whereas they meet two and a half hours later if they travel in the same direction. The faster of the two travels at the speed of

20% discount is offered on an item. By applying a promo code the customer wins 15% cash back. What is the effective discount?