Quantitative Aptitude - Arithmetic Ability Questions

The compound interest earned in two years at 15% per annum is Rs 20640. What is the sum invested (in Rs)?

If the amount received at the end of 2nd and 3rd year at Compound Interest on a certain Principal is Rs 1,800, and Rs 1,926 respectively, what is the rate of interest?

The price of an article is discounted by 25%, to restore to its original value, the new price must be increased by

If cosAcotA/(1 -­ sinA) = x, then the value of x is

In a bag the ratio of red balls to green balls is 4 : 9. If 6 more green balls were added to the bag, the ratio of red balls to green balls would become 1 : 3. How many red balls are there in the bag?

If the population of a town increases by 25% in the first year and increases by 36% in the second year, then what is the average rate (in percentage)of increase in the population?

If 5/2 - (6/5)(x - 15/2) = -x/5, then what is the value of x?

The average age of 19 boys in a class is 21 years. If the teacher's age is included, the average increases to 22 years. What is the teacher's age?