Quantitative Aptitude - Arithmetic Ability Questions

The value of (1 - √2) + (√2 - √3) + (√3 - √4) + ..... + (√15 - √16) is

What is the value of (cot60 + 1/√3) ?

If √20 + √125 = 15.65, then what is the value of √45 + √5?

If a + b = 10 and ab- 13 = -ba - 11, then what is the value of 3ab + 4a2 + 5b2 ?

The simplified form of (x + 3)2 + (x - 1)2 is

Find the length of one side of a rhombus whose area is 24 sq.cm and the sum of the lengths of its diagonals is 14 cm.

If PA and PB are two tangents to a circle with centre O such that ∡APB = 80°. Then ∡AOP = 

A natural number, when divided by 5,6,7 or 8,leaves a remainder of 4 in each case. what is the smallest of all such numbers?