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 

The angle of elevation of the top of a 36 m tall tower from the initial position of a person on the ground was 60 deg. She walked away in a manner that the foot of the tower, her initial position and the final position were all in the same straight line. The angle of elevation of the top of the tower from her final position was 30 deg. How much did she walk from her initial position?

The minimum number of straight lines required to construct the given figure is ___.

From the top of a platform, the angle of elevation of a tower was 30 deg. The tower was 45 mts high and the horizontal distance between the platform and the tower was 40√3 m. What was the height of the platform?

____ are twin prime numbers.

In a triangle the length of the side opposite the angle which measures 60° is 15 cm, what is the length of the side opposite to the angle which measures 90°? 

Which of the following numbers is a prime number?

125 - 73 + 48 - 137 + 99 = ?