Question

a sum of money is invested for 3 years at a certain rate of interest. had the rate of interest been 1% more, it would have fetched rs 18 more than before. find the sum invested?

Answer 1

amount invested --- p
first rate of interest --- r
second rate of interest r + .01

interest at first rate = rp
interest at 2nd rate = p(r+.01)

p(r+.01) - rp = 18
rp + .01p - rp = 18
.01p = 18
p = 18/.01 = 1800