Quantitative Aptitude - Arithmetic Ability Questions

In the following question, four groups of three numbers are given. In each group the second and third number are related to the first number by a Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

Calculate the area (in cm2 ) of a circle of radius 10.5 cm.

If x - y = 6 and xy = 40, then find x2 + y2 ?

If x+19x=4, then 9x2+19x2 is

What is the value of [1 – sin (90 – 2A)] / [1 + sin (90 + 2A)]?

A mobile plan costs Rs. 32 for 6 minutes. What is the approximate cost, in rupees, for 4 minutes?

If {12(a-b)}2+ab=p(a+b)2, then the value of p is 

One-third of Poojitha's age three years ago plus one-half of her age two years from now is twenty years. How old is she now?