Question:
Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 7% simple interest.
Correct Answer
$9128
Solution And Explanation
Solution
Given,
Principal (P) = $5600
Rate of Simple Interest (SI) = 7%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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 × 7% × 9
= $5600 ×7/100 × 9
= 5600 × 7 × 9/100
= 39200 × 9/100
= 352800/100
= $3528
Thus, Simple Interest = $3528
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 + $3528
= $9128
Thus, Amount to be paid = $9128 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) = 7%
And, Time (t) = 9 years
Thus, Amount (A)
= $5600 + ($5600 × 7% × 9)
= $5600 + ($5600 ×7/100 × 9)
= $5600 + (5600 × 7 × 9/100)
= $5600 + (39200 × 9/100)
= $5600 + (352800/100)
= $5600 + $3528 = $9128
Thus, Amount (A) to be paid = $9128 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 7%
This, means, $7 per $100 per year
∵ For $100, the simple interest for 1 year = $7
∴ For $1, the simple interest for 1 year = 7/100
∴ For $5600, the simple interest in 1 year
= 7/100 × 5600
= 7 × 5600/100
= 39200/100 = $392
Thus, simple interest for 1 year = $392
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $392 × 9 = $3528
Thus, Simple Interest (SI) = $3528
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5600 + $3528
= $9128
Thus, Amount to be paid = $9128 Answer
Similar Questions
(1) Calculate the amount due if William borrowed a sum of $3500 at 9% simple interest for 4 years.
(2) Find the amount to be paid if Linda borrowed a sum of $5350 at 7% simple interest for 8 years.
(3) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $10064 to clear the loan, then find the time period of the loan.
(4) Find the amount to be paid if James borrowed a sum of $5000 at 4% simple interest for 7 years.
(5) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 3% simple interest.
(6) Calculate the amount due if Patricia borrowed a sum of $3150 at 10% simple interest for 3 years.
(7) Calculate the amount due if William borrowed a sum of $3500 at 7% simple interest for 4 years.
(8) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 9% simple interest?
(9) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 2% simple interest?
(10) How much loan did Michael borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6360 to clear it?