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 on 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

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

If 5 -­ 5x < 4 -­ x and 2 -­ x < 6 -­ 4x, then x can take which of the following values?

If x - √x = 20; Find the value of √x.

A man, rowing a boat, covers a distance of 16 km in two hours downstream. He covers half the distance in same amount of time when rowing upstream. Calculate the speed of the stream.

In a triangle the length of the side opposite the angle which measures 30° is 9 cm, what is the length of the side opposite to the angle which measures 60°?

Find the volume (in cub.cm) of a hemisphere of diameter 21 cm.

If ax - 4y = -6 has a slope of -3/2. What is the value of a?