Principal lent to Balaji P1 = Rs 5000
Time n1 = 2 years
Let r be the rate of interest per year
Simple interest got from Balaji = \(\frac{pnr}{100}\)
⇒ I1 = \(\frac{5000\times25\times\,r}{100}\)
Again principal let to Charles P2 = Rs 3000
Time (n2) = 4 years
Simple interest got from Charles (I2) = \(\frac{3000\times4\times\,r}{100}\)
Altogether Arun got Rs 2200 as interest.
∴ I1 + I2 = 2200
\(\frac{5000\times25\times\,r}{100}\) + \(\frac{3000\times4\times\,r}{100}\) = 2200
100r + 120r = 2200
220r = 2200
r = \(\frac{2200}{220}\)
= 10 %
Rate of interest per year = 10 %