Question:
Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 3% simple interest.
Correct Answer
$7112
Solution And Explanation
Solution
Given,
Principal (P) = $5600
Rate of Simple Interest (SI) = 3%
Time (t) = 9 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) = $5600 × 3% × 9
= $5600 ×3/100 × 9
= 5600 × 3 × 9/100
= 16800 × 9/100
= 151200/100
= $1512
Thus, Simple Interest = $1512
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 = $5600 + $1512
= $7112
Thus, Amount to be paid = $7112 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 = $5600
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 9 years
Thus, Amount (A)
= $5600 + ($5600 × 3% × 9)
= $5600 + ($5600 ×3/100 × 9)
= $5600 + (5600 × 3 × 9/100)
= $5600 + (16800 × 9/100)
= $5600 + (151200/100)
= $5600 + $1512 = $7112
Thus, Amount (A) to be paid = $7112 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 $5600, the simple interest in 1 year
= 3/100 × 5600
= 3 × 5600/100
= 16800/100 = $168
Thus, simple interest for 1 year = $168
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $168 × 9 = $1512
Thus, Simple Interest (SI) = $1512
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5600 + $1512
= $7112
Thus, Amount to be paid = $7112 Answer
Similar Questions
(1) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $11400 to clear the loan, then find the time period of the loan.
(2) Calculate the amount due if Jennifer borrowed a sum of $3250 at 7% simple interest for 3 years.
(3) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 10% simple interest?
(4) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 4% simple interest.
(5) Calculate the amount due if Karen borrowed a sum of $3950 at 10% simple interest for 4 years.
(6) Richard took a loan of $5200 at the rate of 8% simple interest per annum. If he paid an amount of $8944 to clear the loan, then find the time period of the loan.
(7) How much loan did Richard borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6160 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 $7844 to clear the loan, then find the time period of the loan.
(9) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.
(10) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 3% simple interest?