6,400 रुपये की राशि पर 2 वर्ष के लिए समान दर पर साधारण ब्याज और चक्रवृद्धि ब्याज (वार्षिक रूप से संयोजित) का अंतर 144 रुपये है। वार्षिक ब्याज दर ज्ञात कीजिए।

The difference between simple interest and compound interest (compounded half-yearly) on a sum at the rate of 25% per annum for 1 year is ₹ 4,375. What is the principal amount?

A person invested half of his capital at 10% simple interest and the other half at 10% compound interest (compounded annually) for 2 years. If the total interest earned is ₹ 4,100, find his total capital.