Question

the difference between the compound interest and the simple interest on a certain sum of money at 15% per annum for 3 years is rupees 283. 50 find the sum ​

Answer 1

let principal = rs.P

and rate = 15%p.a.(given)

Time=3 years(given)

compound interest= P{(1+R/100)*t - 1}

= P{(1+15/100)*3 - 1}

P{(100+15/100)*3 - 1}

P{(115/100)*3 - 1}

P{1520875/1000000 - 1}

P{1520875-1000000/1000000}

P{520875/1000000}

P{4167/8000}

rs.4167/8000P= compound interest

Simple Interest = P×R×T/100

P×15×3/100

P× 45/100

P× 9/20

therefore simple Interest= rs.9/20P

C.I. - S.I. = 283.50(given)

4167/8000P - 9/20P = 283.50

4167P - 3600P/8000=283.50

567P/8000= 283.50

P= 283.50×8000/567

P= 4000

therefore the principal = rs. 4000