Question

In simple interest, a sum of money amounts to Rs 6,200 in 2 years and Rs 6,800 in 3 years. Find the principal and rate of interest.

Answer 1

Let the principal P = Rs 100 

If A = 6200 

⇒ Principal + Interest for 2 years = 6200 

A = Rs 7400 

⇒ Principal + Interest for 3 years = 7400 

∴ Difference gives the Interest for 1 year 

∴ Interest for 1 year = 7400 – 6200 

I = 1200 

\(\frac{pnr}{100}\) = 1200 

⇒ \(\frac{p\times1\times\,r}{100}\) = 1200 

If the Principal = 10,000 then 

\(\frac{10000\times1\times\,r}{100}\) = 1200

⇒ r = 12 % 

Rate of interest = 12 % per month