Question:
Calculate the amount due if Susan borrowed a sum of $3650 at 3% simple interest for 4 years.
Correct Answer
$4088
Solution And Explanation
Solution
Given,
Principal (P) = $3650
Rate of Simple Interest (SI) = 3%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $3650 × 3% × 4
= $3650 ×3/100 × 4
= 3650 × 3 × 4/100
= 10950 × 4/100
= 43800/100
= $438
Thus, Simple Interest = $438
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 = $3650 + $438
= $4088
Thus, Amount to be paid = $4088 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 = $3650
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 4 years
Thus, Amount (A)
= $3650 + ($3650 × 3% × 4)
= $3650 + ($3650 ×3/100 × 4)
= $3650 + (3650 × 3 × 4/100)
= $3650 + (10950 × 4/100)
= $3650 + (43800/100)
= $3650 + $438 = $4088
Thus, Amount (A) to be paid = $4088 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 3%
This, means, $3 per $100 per year
∵ For $100, the simple interest for 1 year = $3
∴ For $1, the simple interest for 1 year = 3/100
∴ For $3650, the simple interest in 1 year
= 3/100 × 3650
= 3 × 3650/100
= 10950/100 = $109.5
Thus, simple interest for 1 year = $109.5
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $109.5 × 4 = $438
Thus, Simple Interest (SI) = $438
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3650 + $438
= $4088
Thus, Amount to be paid = $4088 Answer
Similar Questions
(1) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 3 years.
(2) How much loan did Carol borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7755 to clear it?
(3) Elizabeth had to pay $3657 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(4) How much loan did Joshua borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7590 to clear it?
(5) Calculate the amount due if John borrowed a sum of $3200 at 8% simple interest for 3 years.
(6) Calculate the amount due if Joseph borrowed a sum of $3700 at 6% simple interest for 3 years.
(7) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $10921 to clear the loan, then find the time period of the loan.
(8) What amount does David have to pay after 6 years if he takes a loan of $3400 at 7% simple interest?
(9) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 7% simple interest.
(10) If Jessica paid $4050 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.