Quantitative Aptitude - Arithmetic Ability Questions

Identified the odd one from the list below.

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.

The number of diagonals in a pentadecagon is

The simple interest on a sum is 5/9 of the principal for 25 years. What is the rate (in percentage) of interest per annum?

Which of the following numbers is completely divisible by 99?

What is the sum of the measures of all the interior angles of a regular polygon of 6 sides?

The smallest of the fractions among 5/8, 3/4, 13/16, 7/12 is ___.

The value of cos0 deg is