The simple interest on a certain sum of the money at 4 % per annum for 4 years is Rs.80 more than the interest on the same sum for 3 years at 5 % per annum. Find the sum.

The price of sugar is increased by 20%. As a result, a family has to decrease its consumption by 20%. The expenditure of the family on sugar is decreased by

A student multiplies a number by 5/3 instead of 3/5. What is the percentage error in the calculation?

Present age of Ram and Shyam are in the ratio of 4: 5 respectively. Five year hence the ratio of their age becomes 5:6 respectively. What is Ram’s present age?

An amount doubles itself in 5 years simple interest. What is the rate of interest per year?

In the given figure if each of the outer circles have radii ‘R’, then the radius of the inner circle will be:

Costs of two articles were in the ratio of 16: 23. The cost of first articles increases by 10% and that of second by Rs.477. Now the costs of two articles are in a ratio of 11: 20. The price of the second article (in Rs.) in the beginning was-

In a polygon, the sum of the interior angles is double the sum of the exterior angles. What is the number of sides of the polygon?