Question

7. At 4% per annum, the difference between
simple and compound interest for 2 years on a
certain sum of money is Rs. 80. Then the principal
sum is (the interest is compounded annually)
(a) Rs. 40,000
(b) Rs. 50,000
(c) Rs. 5,000
(d) Rs. 4,000​

Answer 1

Answer:

5000

Step-by-step explanation:

Here R = 4%, T = 2 years, CI - SI = 80.

Let Sum be x.

SI = (P * R * T)/100

   = (x * 4 * 2)/100

   = 8x/100

CI = P(1 + R/100)^n - x

   = x(1 + 4/100)^2 - x

   = x(104/100)^2 - x

  = x((104/100))^2 - 1)

 = 0. 0816

∴ CI - SI

= 0.0816 - 0.08

= 0.0016

So,

0.0016 x = 80

x = 5000

Hence, Sum = Rs. 5000