Quantitative Aptitude - Arithmetic Ability Questions

There is a circular garden of radius 21 metres. A path of width 3.5 metres is constructed just outside the garden. What is the area (in metres2) of the path?

If a - b = 2 and ab = 8, then what is the value of a3 - b3?

If 16% of an electricity bill is deducted, Rs 1806 is still to be paid. How much was the bill?

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

Select the odd word/letters/number/number pair from the given alternatives.

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

A pipe, working at full speed, can fill an empty cistern in 1 hour. However, during the first hour it worked at one-twelfth of its capacity, during the second hour at one-ninth of its capacity, during the third hour at one-sixth of its usual capacity and during the fifth hour it was only one -third as efficient as it was supposed to be. A second pipe also displayed similar performance, but if it worked at full speed would have filled the empty cistern in 2 hours. Together with a drain pipe that drained water out of the tank at a constant rate, the empty cistern could be filled in 5 hours, all the three pipes working concurrently. How many hours will it take the drain pipe to empty the filled cistern if no other pipe was functioning during the time?

The mid points of AB and AC of the Δ ABC are P and Q respectively. If PQ = 6 cm, then the side BC is