Quantitative Aptitude - Arithmetic Ability Questions

In the following question, select the odd letter/letters from the given alternatives.

Find the odd word/letters/number pair from the given alternatives

If 2cos2A - 1 = x, then the value of x is

What is the value of Sin 30° + Cos 30°?

What is the slope of the line perpendicular to the line passing through the points (8,­2) and (3,­1)?

If 7 + 3x ≥ 5 ­- x/2 and 2x + 3 ≤ 5 -­ 2x; then x can take which of the following values?

What will be the value of xy, if x2+y2 = 45 and x-y=5 ?

If the diameter of a sphere is 14 cm, then what is the surface area (in sq.cm) of the sphere?