In a certain time, the ratio of a certain principle and interest obtained from it are in the ratio 10 : 3 at 10 % interest per annum. The number of years for which the money was invested is? 

A sum of ₹ 10,000 is lent partly at 8 % and remaining at 10% per annum. If the yearly interest on the average is 9.2 %, the two parts are 

A sum of money was lent at simple interest at certain rate for 3 years. Had it been lent at 2.5 % per annum higher rate, it would have fetched ₹ 540 more. The money lent was 

Equal sum of money are lent to X and Y at 7.5 % per annum for a period of 4 years and 5 years respectively. If the difference in interest, paid by them was 150, the sum lent to each was 

What equal installment of annual payment will discharge a debt which is due as ₹ 848 at the end of 4 years at 4 % per annum simple interest? 

A person lends 40 % of his sum of money at 15 % per annum, 50 % of rest at 10 % per annum and the rest at 18 % per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum? 

The distance between two parallel poles is 40√3 m. The angle of depression of the top of the second pole, when seen from the top of first pole, is 30 °. What will be the height of second tower if the first pole is 100m long? 

The shadow of the tower becomes 60 meters longer when the altitude of the sun changes from 45 ° to 30 °. Then the height of the tower is