Quantitative Aptitude - Arithmetic Ability Questions

If a - b = 3 and a2+b2=25, then the value of ab is

In ∆ABC, ∡A + ∡B = 75 and ∡B + ∡C = 140, then ∡B =

If x+1x = 4, then what is the value of x6+1x6 ?

If a3+1a3 = 2, then the value of a2+1a?

In an army selection process, the ratio of selected to unselected was 3:1. If 60 less had applied and 30 less selected, the ratio of selected to unselected would have been 5:1. How many candidates had applied for the process?

Two students appeared for an examination. One of them secured 16 marks more than the other and his marks were 75% of the sum of their marks. The marks obtained by them are

The lengths of diagonals of a rhombus are 24cm and 10cm the perimeter of the rhombus (in cm ) is :

The 2nd and 6th term of an arithmetic progression are 8 and 20 respectively. What is the 20th term?