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.

If the 3rd and the 5th term of an arithmetic progression are 13 and 21, what is the 13th term?

Find the value of  y(y4 - y2 - y) when y = 5.

In the following question, select the odd letter/letters from the given alternatives.

ΔABC is similar to ΔDEF. If the ratio of similar sides is K:1, the ratio of their areas is

If A is 50% more than B, then B is what percent of A?

Two circles touch each other at point X. Two common tangents of the circles meet at point P and none of the tangents passes through X. These tangents touch the larger circle at points B and C. If the radius of the larger circle is 15 cm and CP = 20 cm, then what is the radius (in cm) of the smaller circle?

The diagonals are not perpendicular in a _____.