A money-lender borrows money at 4% per annum and pays the interest at the end of the year. He lends it at 6% per annum compound interest compounded half yearly and receives the interest at the end of the year. In this way, he gains Rs. 313.50 a year. The amount of money he borrows, is :
1
Rs. 16,000
2
Rs. 15,500
3
Rs. 15,000
4
Rs. 14,500