Question:
Calculate the amount due if Thomas borrowed a sum of $3800 at 5% simple interest for 4 years.
Correct Answer
$4560
Solution And Explanation
Solution
Given,
Principal (P) = $3800
Rate of Simple Interest (SI) = 5%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3800 × 5% × 4
= $3800 ×5/100 × 4
= 3800 × 5 × 4/100
= 19000 × 4/100
= 76000/100
= $760
Thus, Simple Interest = $760
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 = $3800 + $760
= $4560
Thus, Amount to be paid = $4560 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 = $3800
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 4 years
Thus, Amount (A)
= $3800 + ($3800 × 5% × 4)
= $3800 + ($3800 ×5/100 × 4)
= $3800 + (3800 × 5 × 4/100)
= $3800 + (19000 × 4/100)
= $3800 + (76000/100)
= $3800 + $760 = $4560
Thus, Amount (A) to be paid = $4560 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 5%
This, means, $5 per $100 per year
∵ For $100, the simple interest for 1 year = $5
∴ For $1, the simple interest for 1 year = 5/100
∴ For $3800, the simple interest in 1 year
= 5/100 × 3800
= 5 × 3800/100
= 19000/100 = $190
Thus, simple interest for 1 year = $190
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $190 × 4 = $760
Thus, Simple Interest (SI) = $760
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3800 + $760
= $4560
Thus, Amount to be paid = $4560 Answer
Similar Questions
(1) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.
(2) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $7668 to clear the loan, then find the time period of the loan.
(3) How much loan did Paul borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8375 to clear it?
(4) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 3% simple interest?
(5) Linda took a loan of $4700 at the rate of 9% simple interest per annum. If he paid an amount of $8930 to clear the loan, then find the time period of the loan.
(6) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 4% simple interest.
(7) Find the amount to be paid if Michael borrowed a sum of $5300 at 3% simple interest for 7 years.
(8) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 8% simple interest?
(9) If Thomas paid $4104 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(10) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 7% simple interest?