The simple interest on a sum at 3% p.a in 3 years is ₹315. What is the compound interest on the same sum at 4% p.a in 2 years, interest compounded yearly?

₹285.6

We know ,

Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)

315 = \(\frac{Principal × 3 × 3}{100}\) 

Principal = 3500

With compound interest , Amount = Principal × ( 1 + \(\frac{r }{100 }\) )^t

= 3500 × ( 1 + \(\frac{4 }{100 }\) )²

= 3500 × \(\frac{26 }{25 }\) × \(\frac{26 }{25 }\)

= 3785.6

Amount = Principal + Compound  Interest

3785.6 = 3500 +  Compound Interest

Compound Interest = 3785.6 - 3500 = Rs.285.6