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 at double the rate of simple interest doubles itself in 10 years. In how much time will that amount be triple of itself?

Which amount will be Rs 520 in 5 years with simple interest and Rs 568 in 7 years?

The simple interest on a sum  of money is $$8\over 25$$ of the sum. If the number of years is numerically half the rate percent per annum, then the rate percent per annum is 

A certain sum of money lent out at simple interest amounts to Rs. 2400 in 4 years and Rs. 3000 in 6 years. Find the rate of interest per annum?

In what time will the simple interest be $$ {2\over5} $$ of the principal at 8% per annum? 

A sum of money was invested at a certain rate of simple interest for 2 years. Had it been invested at 1% higher rate, it would have fetched Rs.192 more interest. The sum of money is-

A sum of money becomes two times of itself in 8 years at simple interest, and it becomes four times of itself in 2 years at compound interest, when interest is compounded annually. Find the ratio of the rate of simple interest to the rate of compound interest offered per year.