Consider a planet whose mass and radius are both twice the mass and radius of Earth. The acceleration due to gravity on the surface of the planet is 'n' times that on Earth. The value of n is:
A bank offers 10% compound interest per half year. A customer deposits Rs. 2000 each on 1st January and 1st July of a year. At the end of the year, the amount he would have gained by way of interest is