A sum was lent at 20%p.a compound interest, the interest being compounded annually. Rs.1200 was paid back after 1 year. After another year Rs. 1440 was repaid to clear the loan. Find the sum lent.
R = 20 % P.A
Paid back after 1st year = 1200
Paid back after year to clear the loan = 1440
Let, P =