Question:
Calculate the amount due if Joseph borrowed a sum of $3700 at 10% simple interest for 4 years.
Correct Answer
$5180
Solution And Explanation
Solution
Given,
Principal (P) = $3700
Rate of Simple Interest (SI) = 10%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 4
= $3700 ×10/100 × 4
= 3700 × 10 × 4/100
= 37000 × 4/100
= 148000/100
= $1480
Thus, Simple Interest = $1480
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 + $1480
= $5180
Thus, Amount to be paid = $5180 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) = 10%
And, Time (t) = 4 years
Thus, Amount (A)
= $3700 + ($3700 × 10% × 4)
= $3700 + ($3700 ×10/100 × 4)
= $3700 + (3700 × 10 × 4/100)
= $3700 + (37000 × 4/100)
= $3700 + (148000/100)
= $3700 + $1480 = $5180
Thus, Amount (A) to be paid = $5180 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 10%
This, means, $10 per $100 per year
∵ For $100, the simple interest for 1 year = $10
∴ For $1, the simple interest for 1 year = 10/100
∴ For $3700, the simple interest in 1 year
= 10/100 × 3700
= 10 × 3700/100
= 37000/100 = $370
Thus, simple interest for 1 year = $370
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $370 × 4 = $1480
Thus, Simple Interest (SI) = $1480
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3700 + $1480
= $5180
Thus, Amount to be paid = $5180 Answer
Similar Questions
(1) Barbara had to pay $3763 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(2) Thomas took a loan of $5600 at the rate of 8% simple interest per annum. If he paid an amount of $9632 to clear the loan, then find the time period of the loan.
(3) William had to pay $4025 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.
(4) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 5% simple interest.
(5) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 8% simple interest?
(6) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 9% simple interest.
(7) How much loan did Lisa borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6957.5 to clear it?
(8) Susan took a loan of $5300 at the rate of 8% simple interest per annum. If he paid an amount of $9116 to clear the loan, then find the time period of the loan.
(9) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7647.5 to clear it?
(10) Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 4% simple interest.