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.

Two ships are sailing in the sea on the two sides of a light house. The angle of elevation of the top of the light house as observed from the two ships are 30° and 45° respectively. If the light house is 100m high, the distance between the two ships is :(take √3=1.73)

If the standard deviation of a population is 7, what would be the population variance?

Rearrange the jumbled up letters in their natural sequence and find the odd one out.

What is the difference (in Rs) between compound interest (compounded annually) and simple interest for 3 years on a principal of Rs 4000 at the rate of 30% per annum?

What is the sum of all prime numbers between 60 and 80?

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.

A balloon is connected to a meteorological station by a cable of length 130 m, inclined at 60 deg to the horizontal. Find the height of the balloon from the ground. Assume that there is no slack in cable.