A sum of money is lent at S.I for 8 years. If the same amount is paid at 5% higher, Ramesh would have got Rs. 100 more. Find the Principal?

A.200
B.240
C.250
D.300
Answer:C

Explanation: 

Let the Principal be P Rs.
Let the first rate of interest be r
The difference in r is 5
5 x P x N = (Difference in interest) x 100
5 x P x 8 = 100 x 100
p = 100 x 100 / 5 x 8
  = Rs. 250