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 altitude of an equilateral triangle whose side is 12 cm?

Both A and B together can complete a work in 20 days and B alone can complete the same work in 36 days. In how many days will A alone complete the work?

A boy buys 5 pencils at Rs 3 each, 3 erasers at Rs 2 each and 3 sharpeners at Rs 5 each. What is the average expenditure (in Rs) per article?

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

What is the value of [2 sin (45 + θ) sin (45 – θ)]/cos 2θ?

What is the equation of the line whose y­-intercept is ­3/4 and making an angle of 45° with the positive x-­axis?

If 8x/3 + [7(5 - 2x/3)]/2 = 1/2 , then what is the value of x?