Quantitative Aptitude - Arithmetic Ability Questions

A man is 3 years older than his wife and four times as old as his son. If the son becomes 15 years old after 3 years. Then what is the present age of the wife?

If 31x + 31y = 403, then what is the average of x and y?

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 given alternatives.

A line passing through the origin perpendicularly cuts the line 3x - 2y = 6 at point M. Find M?

If cot(A/2) = x, then x is equal to

2cos[(C+D)/2]sin[(C-D)/2] is equal to

What is the x-intercept of line joining (4, 2) and (6, 3)?

A car travels from A to B with 40 Km/h and returns from B to A with 60 Km/h. Its average speed during the whole journey is