Quantitative Aptitude - Arithmetic Ability Questions

If a + b = 1, then a4 + b4 - a3 - b3 - 2a2b2 + ab is equal to

Find the value of '?' in 512 × 125 ÷ 15625 = 3125 × 25?

A bag contains coins of denominations Rs.1, Rs.5 and Rs.10. Assuming there are equal number of Rs.1, Rs.5 and Rs.10, what will be the total number of coins in the bag be if the total money is Rs. 368?

Find the total surface area (in cm2 ) of a hemisphere of diameter 42 cm.

Five men or ten women can complete a job in 20 days. In how many days can 3 men and 4 women complete it?

A non-zero number is greater than 7 times its reciprocal by 9.3. What is the number?

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?

Two donkeys are standing 400 meters apart. First donkey can run at a speed of 3 m/sec and the second can run at 2 m/sec. If two donkeys run towards each other after how much time (in sec) will they bump into each other?