Ramesh deposits ₹ 2400 per month in a recurring deposit account deposit scheme of a bank for one year. If he gets ₹ 1248 as interest at the time of maturity, find the rate of interest. Also, find the maturity value of this deposit.

A solid is in the form of a right circular cylinder with a hemispherical shape at one end and a cone at the other end. Their common diameter is 4.2 cm and the heights of the cylindrical and conical portions are 12 cm and 7 cm respectively. Find the volume of the solid.