1.  What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years?
A. 1 : 3
B. 1 : 4
C. 2 : 3
D. Data inadequate
E. None of these

Answer: Option C

Explanation:

Let the principal be P and rate of interest be R%.

Required ratio =
P x R x 6
100
= 6PR = 6 = 2 : 3.
P x R x 9
100
9PR 9