What will be the ratio of the simple interest earned by a certain amount at the same rate of interest for 6 years and that for 9 years?

Question: What will be the ratio of the simple interest earned by a certain amount at the same rate of interest for 6 years and that for 9 years?

Solution:
Let,
the principal be Tk P and the rate of interest be R% per annum.
We know,
Simple Interest, I = Pnr/100
Simple interest for 6 years = (P × R × 6)/100.
Simple interest for 9 years = (P × R × 9)/100.

∴ Ratio = (P × R × 6)/100 : (P × R × 9)/100
= 6 : 9
= 2 : 3.

So, the ratio is 2 : 3