CAT 1995 — QA Question 15
Simple InterestEasy
A man invests Rs.3,000 at the rate of 5% per annum. How much more should he invest at the rate of 8%, so that he can earn a total of 6% per annum?
Answer & solution
Correct answer: Rs. 1,500
- A
Rs. 1,200
- B
Rs. 1,300
Rs. 1,500
- D
Rs. 2,000
Solution
Using alligation, the ratio of the amounts invested at both the rates = 2 : 1.
Since he has invested Rs.3,000 at 5%, he should further invest Rs.1,500 at 8% to earn a total interest of 6% per annum.
Alternative method:
Let the amount invested at 8% be Rs. x.
Then,
⇒ 0.02x = 30 ⇒ x = 1,500
∴ He should further invest Rs.1,500 at 5% to earn a total interest of 6% per annum.