An amount of Rs. 680 was invested at 6% rate of interest and another sum of money was invested at 10% interest. If the average interest on the total at the end of the year was 7.5%, how much was invested at 10%?

Answer: Option A

Solution

Answer: Option A

Solution:

Now, $$\frac{680}{x}=\frac{2.5}{1.5}$$
Or, $$x=\frac{680\times 3}{5}$$
Hence, x = Rs. 408