Question

18. The simple interest on a sum of money is of the principal and the number of years is equal to the rate per cent
per annum. What is the rate per cent per annum?​

Answer 1

Answer: assume p =100

So si =prt/100

100=100*r2/100

100 cancels 100

Now r2=100 r =10

Answer 2

Let the principal be P. Rate of interest be R% According to the question, Time=R

4P

Simple interest = 9

SI = (PTR) 100

4P (PTR) 9 100

4P (P x R x R) 9 100

4P 9 1 (P x R?) 100 → R? = 100 x > R = 10 x 2 3 4 9 20 3

4 R2 9 100

Therefore, rate of interest is 20 3 % or 6 %.