On what sum will the compound interest for 2 years at 4% per annum be ₹5712?

A man invests ₹1200 for two years at compound interest. After one year the money amounts to ₹1275. Find the interest for the second year correct to the nearest rupee.

At what rate percent will ₹2000 amount to ₹2315.25 in 3 years at compound interest?