A sum of money at simple interest amounts to Rs. 14,160 in 3 years. If the rate of interest is increased to 25%, the same sum amounts to Rs. 14,700 in the same time. The rate of interest is 5% $5 \frac{1}{2}$ 6% 7%
A sum of money at simple interest amounts to Rs. 14,160 in 3 years. If the rate of interest is increased to 25%, the same sum amounts to Rs. 14,700 in the same time. The rate of interest is