Quantitative Aptitude - Arithmetic Ability Questions

What is the value of {sin (90 – x) cos [π – (x – y)]} + {cos (90 – x) sin [π – (y – x)]}?

In the following question, select the odd word from the given alternatives.

54% of 4000 is

Tanya got an increment of 15% in her salary. If her enhanced salary is Rs.14,030. What was her original salary?

Find co-ordinates of the mid point of the segment joining points C (3,-5) and D (-7,3).

What will be the value of r2+p2+s2-rp-ps-rs when r = 4, p = 2, s = 8?

If cot 60° + cosec 60° = x, then the value of x is

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?