In how many years will `rs 35000` will amount to `rs 87500` at `10%p.a`. simple interest ?

In how many years will Rs.2,000 amounts to Rs.2,420 at 10% per annum amount interest?

A sum of Rs . 400 becomes Rs 448 at simple interest in 2 years . In how many years will the sum of Rs. 550 amounts to Rs . 682 at the same rate?

In how many years will Rs. 400 amount to Rs. 441 at 5% compound interest?

In how many years will the amount of Rs. 1200 double itself under simple interest system of 4% p.a. ?

In how many years Rs. 3000 amount to Rs. 5184 at 20% per annum compound interest ?

In how many years, a sum of Rs. 500 at 5% per annum at simple interest amount to Rs. 600?