Quantitative Aptitude - Arithmetic Ability Questions

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?

What is the third proportional to 9 and 15?

If the shopkeeper sells an item at Rs 450 which is marked as Rs 600, then what is the discount he is offering?

Find the odd words/letter/number from the given alternatives:

If cost price of 5 cars is equal to selling price of 4 cars. Find the percentage of profit or loss?

What is the difference of the factors of the expression x2 + (1/x2) – 6?

If x+1x = 4, then what is the value of x6+1x6 ?

The mean of marks secured by 30 students in division-A of class X is 67, 55 students of division-B is 63 and that of 40 students of division-C is 61. What is the mean of marks of the students of three divisions of Class X?