Quantitative Aptitude - Arithmetic Ability Questions

A shopkeeper increases the price of an object by 40% and then sells it at 25% discount on the marked price. If the selling price of such an object be Rs. 2100, its cost price for the shopkeeper was ?

A man is 3 years older than his wife and four times as old as his son. If the son becomes 15 years old after 3 years. Then what is the present age of the wife?

Raja and Kundan together can build a wall in 20 days, Kundan and Mahesh build the same wall in 30 days and Mahesh and Raja can build the same wall in 24 days. In how many days can all the three complete the same wall while working together?

(45.004% of 1439.97 –15.99% of 2249.97) ÷ 35.98 = ?

In the given figure, PQ = 30, RS = 24 and OM = 12, then what is the value of ON?

Diameter of a car wheel is 21 cm. A car driver moving at the speed of 66 km/hr takes 36 seconds to reach a destination. How many revolutions will the wheel make during the journey?

The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observations is

Two points P and Q are at the distance of x and y (where y > x) respectively from the base of a building and on a straight line. If the angles of elevation of the top of the building from points P and Q are complementary, then what is the height of the building?