CAT 2019 Slot 1 — QA Question 28
Simple InterestEasy
Amala, Bina, and Gouri invest money in the ratio 3 : 4 : 5 in fixed deposits having respective annual interest rates in the ratio 6 : 5 : 4. What is their total interest income (in Rs) after a year, if Bina's interest income exceeds Amala's by Rs 250?
Answer & solution
- A
7000
7250
- C
6350
- D
6000
Solution
Let the amount invested by Amala, Bina and Gouri be 3x, 4x and 5x respectively.
Also, let the respective rates be 6r, 5r and 4r.
So, the respective ratio of simple interest is (3x × 6r) : (4x × 5r) : (5x × 4r) = 18xr : 20xr : 20xr.
Bina's interest income exceeds Amala's by Rs 250.
∴ 20xr − 18xr = 250.
∴ xr = 125.
Total interest income = 18xr + 20xr + 20xr = 58xr = 58 × 125 = Rs. 7250.
Hence, option (b).