4800 रुपये पर वार्षिक रूप से संयोजित R% की दर से 2 वर्ष बाद अर्जित ब्याज 1008 रुपये है। उसी राशि पर (R + 5)% प्रति वर्ष की दर से 3 वर्ष बाद अर्जित साधारण ब्याज कितना होगा?

A sum becomes 25 times of itself when invested for 48 years at r% simple interest per annum. Find the compound interest earned if Rs. 51,200 is invested at r% per annum when interest is compounded half-yearly, for 1.5 years.

Simple interest on a certain sum at 4% per annum for 2 years is ₹80. What is the compound interest on the same sum for the same period at the same rate?