If Rs 64 amounts to Rs 83.20 in 2 years on simple interest, then how much will Rs 86 amount to in 4 years at the same rate percent per annum ?

A sum of money at compound interest double itself in 12 years. It will become 16 times of itself in:

A sum of ₹ 80,000 is invested at 6% p.a. at simple interest for the first year, then 8% p.a. for the next 2 years (still simple interest). What is the total interest earned over the 3 year period?

Mr. X invested one fourth of his capital at 8%, one third at 7% and the remaining part at 10%. If his annual simple interest on this investment is Rs 510, then the total capital invested by Mr. X is?

Find the compound interest on Rs. 16,000 at 20% per annum for 9 Months, compounded quarterly.

In what time will the simple interest on ₹2200 at 6% per annum be the same as that on ₹1650 at 9% per annum in 10 years?

A sum of Rs. 1500 is invested at 5% p.a. simple interest. If the interest is added to the principal after every 10 years, the amount will become Rs. 3000 after :