Quantitative Aptitude - Arithmetic Ability Questions

In a class, there were 9 boys and some girls. In a test the mean score obtained by the boys was 12 while that obtained by the girls was 14. If the overall average was 13.1, what was the total number of students in the calss?

ax + 5y = 8 has slope of -4/3. What is the value of a?

An investor invested his saving in the stock market. The value of his investments increased by 12% and 9% in the first year and the second year respectively. If the value of his investments after two years became Rs 97,664 then how much had he invested (in Rs)?

If a sum of Rs.12500 is invested for 1 year at 12% per annum interest being compounded semi­-annually, then interest earned is

Shams invested Rs. 5000 at 10% per annum compound interest. After n years, Shams received Rs. 1655 more. Find the value of n.

The amount of simple interest accrued on an amount of Rs 28,500 in seven years is Rs 23,940 What is the rate of interest p.c.p.a ?

PQRS is a square, M is the mid-point of PQ and N is a point on QR such that NR is two-third of QR. If the area of ΔMQN is 48 cm2 , then what is the length (in cm) of PR ?

What is the ratio of simple interest earned on certain amount at the rate of 12% p.a. for 9 years and that for 12 years?