A person reaches his destination 32 minutes late if his speed is 6 km/h, and reaches 18 minutes before time if his speed is 7 km/h. Find twice the distance (in km) of his destination from his starting point.
Ramesh deposited Rs. 15600 in a fixed deposit at the rate of 10% per annum simple interest. After every second year, he adds his interest earnings to the principal. The total interest at the end of fourth year is