Question

The simple interest on a sum of money is 1/9 of the sum.The number of years is numerically equal to the rate percent per annum. The rate percent per annum is?

Answer 1

I = PRT
you told me I = 1/9P --> P = 9I
you told me r = t, where r is a stated percent

I = 9I(r/100)(r)
1 = (9/100)r^2
r^2 = 100/9
r = 10/3 = 3.3333..
<b> the rate is 3 1/3%</b>

check:
suppose we have $1000 for 10/3 years at 3 1/3 %
I = 1000(10/3)(10/300) = 111.11

and 1/9 of 1000 = 111.11
My answer is correct

Answer 2

Thanks