Question

the difference in compound interest and simple interest on a certain amount at 10% per annum at the end of the third years is rs 620 .what is the principal amount?

Answer 1

Answer:

Step-by-step explanation:S.I=(X*10*3/100)

=3X/10

C.I=[X(1+10/100)^3-X]

=331/1000

S.I-C.I

331X/1000-3X/10=620

31X/1000=620/1

31X=620000

X=620000/31

X=20000

Answer 2

Answer:

20,000 is the principal amount.

Step-by-step explanation:

Let,

amount be X

years =3 (given)

amount at end of 3 year be =620(given)

• Simple intrest= X×10×3/100

=3X/10

• compound interest= (X(1+10/100)³-X)

=331X/1000

compound interest -simple interest

=3X/10-331X/10=62P

=31X/1000=620

=31X=620000

=X=2000.

Principal amount= 20,000.

(#SPJ3)