Question:
Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 3 years.
Correct Answer
$4508.5
Solution And Explanation
Solution
Given,
Principal (P) = $3550
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) = $3550 × 9% × 3
= $3550 ×9/100 × 3
= 3550 × 9 × 3/100
= 31950 × 3/100
= 95850/100
= $958.5
Thus, Simple Interest = $958.5
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 = $3550 + $958.5
= $4508.5
Thus, Amount to be paid = $4508.5 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 = $3550
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 3 years
Thus, Amount (A)
= $3550 + ($3550 × 9% × 3)
= $3550 + ($3550 ×9/100 × 3)
= $3550 + (3550 × 9 × 3/100)
= $3550 + (31950 × 3/100)
= $3550 + (95850/100)
= $3550 + $958.5 = $4508.5
Thus, Amount (A) to be paid = $4508.5 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 $3550, the simple interest in 1 year
= 9/100 × 3550
= 9 × 3550/100
= 31950/100 = $319.5
Thus, simple interest for 1 year = $319.5
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $319.5 × 3 = $958.5
Thus, Simple Interest (SI) = $958.5
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3550 + $958.5
= $4508.5
Thus, Amount to be paid = $4508.5 Answer
Similar Questions
(1) Barbara took a loan of $5100 at the rate of 6% simple interest per annum. If he paid an amount of $7854 to clear the loan, then find the time period of the loan.
(2) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $10281 to clear the loan, then find the time period of the loan.
(3) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.
(4) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 3% simple interest?
(5) William took a loan of $5000 at the rate of 6% simple interest per annum. If he paid an amount of $7700 to clear the loan, then find the time period of the loan.
(6) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 10% simple interest?
(7) Elizabeth took a loan of $4900 at the rate of 6% simple interest per annum. If he paid an amount of $7546 to clear the loan, then find the time period of the loan.
(8) Calculate the amount due if Mary borrowed a sum of $3050 at 7% simple interest for 4 years.
(9) Calculate the amount due if Michael borrowed a sum of $3300 at 10% simple interest for 4 years.
(10) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $10030 to clear the loan, then find the time period of the loan.