Quantitative Aptitude - Arithmetic Ability Questions

The average weight of 25 candles is 40 grams. If some candles of weight 50 grams each were removed, then average weight becomes 37.5 grams. How many candles of weight 50 grams each were removed? 

A librarian purchased 60 story books for his library. But he found that he could get 4 extra books by spending Rs 336 more and then the overall average price per book would be reduced by Re 1. The previous average price of each book was

How much simple interest will Rs. 4000 earn in 18 months at 12% per annum?

Type 1 workers can do three times the work of Type 2 workers. Twelve Type 1 workers can complete a task in 10 days. How many days would it have taken 4 Type 1 and 8 Type 2 workers to complete the same task?

X, Y and Z can do a piece of work in 30, 40 and 50 days respectively. All three of them began the work together but Y left 4 days before completion of the work. In how many days was the work completed?

What is the Compound interest on Rs. 5000 in 3 years, if the rate of interest is 4% for the first year, 3% for the second year and 2% for the third year?

Aditya got 78% marks in the examination. If he secured 663 marks, find the maximum marks.

If the standard deviation of a population is 10, what would be the population variance?