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 given options.

Find the odd word/letters/numbers pair from the given alternatives.

The point P(5,-2) divides the segment joining the points (x,0) and (0,y) in the ratio 2:5. What is the value of x and y?

If 2+aa + 2+bb + 2+cc = 4, then the value of ab+bc+caabc is

What is the value of (1 + cotA)2 + (1 -­ cotA)2?

If two marbles are picked at random, what is the probability that either both are red or both are green?

Mahmood can do a piece of work in 40 hours. If he is joined by Janaki who is 50% more efficient, in what time will they together finish the work?

The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is: