Question

this difference between the SI and CI on a certain sum of money for 2 years 4 percent per annum is rupees 20. find the sum

Answer 1

tum fitjee jate ho kya

Answer 2

The sum is Rs 12500.

We know, Compound Interest (C.I.) is given as:

C.I. = P[ (1 + r/100)ⁿ - 1]

where P is the Principal amount,

r is the rate of interest = 4% p.a.

n is the time period = 2 years.

Putting these values, we get C.I. as:

CI = P[ (1 + 4/100)² - 1] = P[ (26/25)² - 1] = P[ (676-625)/625] = 51P/625

Also, Simple Interest (S.I.) is given as :

S.I. = (P × r × n) /100

Putting the values of r,n we get:

S.I. = P (4 × 2)/100 = 2P/25

Since, SI<CI, we write their difference as:

Difference = CI - SI = 51P/625 - 2P/25 = (51P - 50P)/625 = P/625

This difference is equal to Rs 20

So, P/625 = 20

Thus P = Rs (20 × 625) = Rs 12500

Thus principal is Rs 12500