CAT 2022 Slot 1 QA Q16 Interest

Question 16 of the Quantitative Ability (QA) section, CAT 2022 Slot 1, with CAT's official answer and a worked solution.

Alex invested his savings in two parts. The simple interest earned on the first part at 15% per annum for 4 years is the same as the simple interest earned on the second part at 12% per annum for 3 years. Then, the percentage of his savings invested in the first part is

A
62.5%
B
37.5%
C
60%
D
40%

Answer: (B) 37.5% Interest MCQ

Solution

Let the parts be \(x\) and \(y\). Equal interest: \(x \times 15 \times 4 = y \times 12 \times 3\), i.e. \(60x = 36y\).
\(x : y = 36 : 60 = 3 : 5\).
First part \(= \frac{3}{8} = 37.5\%\) of savings.