A sum of Rs. 12800 is invested partly at 15% per annum and the remaining at 12% per annum simple interest. If the total interest at the end of 3 years is Rs. 5085, then how much money was invested at 15% per annum?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e Rs. 5300
Let x amount is invested at 15% rate and (12800 - x) amount is invested at 12% rate:
⇒ x × 0.15 × 3 + (12800 - x) × 0.12 × 3 = 5085
⇒ 0.15x + 1536 - 0.12x = 1695
⇒ 0.03x = 1695 - 1536 = 159
⇒ x = 159 × 100/3 = 5300
Hence,
Rs. 5300 are invested at 15% per annum.