Question: The simple interest received on a sum for 40 years is 2/5 of the sum. what is the annual rate of interest?

1. 1.5 percent
2. 2 percent
3. 1 percent
4. 3 percent

Answer: 3. 1 percent

Solution:
formula S.I= PXRXT/(100)
2/5X = X(R)(40)/(100)
R= 1 percent