Question:
Calculate the amount due if Joseph borrowed a sum of $3700 at 9% simple interest for 3 years.
Correct Answer
$4699
Solution And Explanation
Solution
Given,
Principal (P) = $3700
Rate of Simple Interest (SI) = 9%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% per annum.
Method (1) Using Formula
Calculation of Simple Interest
Formula to Calculate Simple Interest
Simple Interest (SI) = Principal × Rate × Time
Thus, Simple Interest (SI) = $3700 × 9% × 3
= $3700 ×9/100 × 3
= 3700 × 9 × 3/100
= 33300 × 3/100
= 99900/100
= $999
Thus, Simple Interest = $999
Calculation of Amount
The total money paid to the lender by a borrower is called the Amount.
In other words, sum of priciple and interest is called the Amount.
Formula to Calculate the Amount
Amount = Principal + Interest
Thus, Amount = $3700 + $999
= $4699
Thus, Amount to be paid = $4699 Answer
Method (2)
Calculation of Amount when Principal, Rate of Simple Interest and Time are given
Calculation of Amount directly using Principal, SI, and Time
Formula to calculate the Amount
Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)
⇒ A = P + PRT
Here in the question, P = $3700
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 3 years
Thus, Amount (A)
= $3700 + ($3700 × 9% × 3)
= $3700 + ($3700 ×9/100 × 3)
= $3700 + (3700 × 9 × 3/100)
= $3700 + (33300 × 3/100)
= $3700 + (99900/100)
= $3700 + $999 = $4699
Thus, Amount (A) to be paid = $4699 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 9%
This, means, $9 per $100 per year
∵ For $100, the simple interest for 1 year = $9
∴ For $1, the simple interest for 1 year = 9/100
∴ For $3700, the simple interest in 1 year
= 9/100 × 3700
= 9 × 3700/100
= 33300/100 = $333
Thus, simple interest for 1 year = $333
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $333 × 3 = $999
Thus, Simple Interest (SI) = $999
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3700 + $999
= $4699
Thus, Amount to be paid = $4699 Answer
Similar Questions
(1) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 8% simple interest.
(2) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 5% simple interest?
(3) Find the amount to be paid if Susan borrowed a sum of $5650 at 6% simple interest for 7 years.
(4) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $10132 to clear the loan, then find the time period of the loan.
(5) Find the amount to be paid if James borrowed a sum of $5000 at 5% simple interest for 8 years.
(6) Calculate the amount due if Robert borrowed a sum of $3100 at 7% simple interest for 3 years.
(7) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6970 to clear the loan, then find the time period of the loan.
(8) Donald took a loan of $7000 at the rate of 6% simple interest per annum. If he paid an amount of $11200 to clear the loan, then find the time period of the loan.
(9) Calculate the amount due if Sarah borrowed a sum of $3850 at 6% simple interest for 4 years.
(10) Jennifer took a loan of $4500 at the rate of 9% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.