Question:
Find the amount to be paid if David borrowed a sum of $5400 at 3% simple interest for 8 years.
Correct Answer
$6696
Solution And Explanation
Solution
Given,
Principal (P) = $5400
Rate of Simple Interest (SI) = 3%
Time (t) = 8 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) = $5400 × 3% × 8
= $5400 ×3/100 × 8
= 5400 × 3 × 8/100
= 16200 × 8/100
= 129600/100
= $1296
Thus, Simple Interest = $1296
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 = $5400 + $1296
= $6696
Thus, Amount to be paid = $6696 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 = $5400
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 8 years
Thus, Amount (A)
= $5400 + ($5400 × 3% × 8)
= $5400 + ($5400 ×3/100 × 8)
= $5400 + (5400 × 3 × 8/100)
= $5400 + (16200 × 8/100)
= $5400 + (129600/100)
= $5400 + $1296 = $6696
Thus, Amount (A) to be paid = $6696 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 $5400, the simple interest in 1 year
= 3/100 × 5400
= 3 × 5400/100
= 16200/100 = $162
Thus, simple interest for 1 year = $162
Therefore, simple interest for 8 years
= Simple interest for 1 year × 8
= $162 × 8 = $1296
Thus, Simple Interest (SI) = $1296
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5400 + $1296
= $6696
Thus, Amount to be paid = $6696 Answer
Similar Questions
(1) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 10% simple interest?
(2) If Mark paid $5280 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.
(3) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9536 to clear the loan, then find the time period of the loan.
(4) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 10% simple interest?
(5) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $9460 to clear the loan, then find the time period of the loan.
(6) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 2% simple interest?
(7) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 5% simple interest.
(8) Betty took a loan of $6500 at the rate of 7% simple interest per annum. If he paid an amount of $10140 to clear the loan, then find the time period of the loan.
(9) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 2% simple interest?
(10) Find the amount to be paid if James borrowed a sum of $5000 at 8% simple interest for 7 years.