Aditya have Rs. 1500 in his hand in which he invests Rs. 500 for 3 years and Rs. 700 for 2 years and remaining for 4 years at the same rate of simple interest. If the sum of all the interest he received is Rs. 615, find the rate of interest per annum.
1
10%
2
12%
3
15%
4
14%
5
13%