Quantitative Aptitude - Arithmetic Ability Questions

In the following question, four number pairs are given. The number on left side of (–) is related to the number of the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

What is the value of Sec 30° + Tan 60°?

The point R(a,b) is first reflected in origin to R1 and R1 is reflected in x­axis to (­-4,2). The co-­ordinates of point R are

If cos -225° = x, then the value of x is

A bag contain equal number of 1 rupee, 50 paisa and 25 paisa coins. If the total amount is Rs 105, then how many coins of each type are there?

What is the value of a-b when a2+b2-6a-6b+18 = 0 ?

Δ XYZ is right angled at Y. If m∠Z = 60°, what is the length of YZ (in cm), if ZX = 3√3 cm?

If the standard deviation of a population is 6.5, what would be the population variance?