A worker borrowed some money on simple interest at the rate of 6% p. a. for the first 3 years, at the rate of 9% p. a. for the next 3 years, and at the rate of 14% p. a. for the period beyond 6 years. If he paid a total interest of Rs. 6,490 at the end of 7 years, how much money did he borrow?
1. Rs. 12,500
2. Rs. 11,000
3. Rs. 12,000
4. Rs. 10,000
1. Rs. 12,500
2. Rs. 11,000
3. Rs. 12,000
4. Rs. 10,000
Correct Answer – Option 2 : Rs. 11,000
Given:
A worker borrowed some money on simple interest at the rate of 6% p. a. for the first 3 years, at the rate of 9% p. a. for the next 3 years, and at the rate of 14% p. a. for the period beyond 6 years. If he paid a total interest of Rs.6,490 at the end of 7 years.
Concept used:
Simple interest
Calculation:
Let the principal be x = 100
Si at the rate of 6% p. a. for 3 years
⇒ 6 × 3 × x = 18x
Si at the rate of 9% p. a. for 3 years
⇒ 9 × 3 × x = 27x
Si at the rate of 14% p. a. for 1 year
⇒ 14 × x = 14x
As per the question,
⇒ 18x + 27x + 14x = 6490
⇒ 59x = 6490
⇒ x = 110
∴ Principal = Rs.11000