Multiple choice

Mohit invested an amount of Rs. 18,000 at the rate of 6% simple interest and another amount at the rate of 10% simple interest. The total interest earned at the end of one year on the amount invested becomes 7% p.a. Find the total amount invested.

  1. Rs. 20,000

  2. Rs. 22,000

  3. Rs. 24,000

  4. Rs. 25,000

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the second amount be x. Total interest = 0.06(18000) + 0.10(x) = 0.07(18000 + x). 1080 + 0.1x = 1260 + 0.07x. 0.03x = 180, so x = 6000. Total investment = 18000 + 6000 = 24000.

AI explanation

Using the alligation method, the ratio of the amount invested at 6% to the amount invested at 10% is (10 - 7) : (7 - 6), which equals 3 : 1. The first amount is 3 parts, which equals Rs. 18000, meaning one part equals Rs. 6000. The total amount invested is 4 parts, so 18000 + 6000 = Rs. 24000.

Keep practicing — related questions