A person invested a sum of Rs.P for 2 years, which is compounded annually at a rate of r% p a. Another person invested the same sum for same period at same rate at simple interest. The difference in their amounts after 2 years is found to be Rs.4P. Find the rate of interest at which they have invested their sums.
None of these
Principal = P
Rate = R%
Difference B/W C.I and S.I = D = PR2/1002
R = 200 %