Question:
Calculate the amount due if William borrowed a sum of $3500 at 8% simple interest for 3 years.
Correct Answer
$4340
Solution And Explanation
Solution
Given,
Principal (P) = $3500
Rate of Simple Interest (SI) = 8%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $3500 × 8% × 3
= $3500 ×8/100 × 3
= 3500 × 8 × 3/100
= 28000 × 3/100
= 84000/100
= $840
Thus, Simple Interest = $840
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 = $3500 + $840
= $4340
Thus, Amount to be paid = $4340 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 = $3500
Rate of Simple Interest (SI) or (R) = 8%
And, Time (t) = 3 years
Thus, Amount (A)
= $3500 + ($3500 × 8% × 3)
= $3500 + ($3500 ×8/100 × 3)
= $3500 + (3500 × 8 × 3/100)
= $3500 + (28000 × 3/100)
= $3500 + (84000/100)
= $3500 + $840 = $4340
Thus, Amount (A) to be paid = $4340 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 8%
This, means, $8 per $100 per year
∵ For $100, the simple interest for 1 year = $8
∴ For $1, the simple interest for 1 year = 8/100
∴ For $3500, the simple interest in 1 year
= 8/100 × 3500
= 8 × 3500/100
= 28000/100 = $280
Thus, simple interest for 1 year = $280
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $280 × 3 = $840
Thus, Simple Interest (SI) = $840
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3500 + $840
= $4340
Thus, Amount to be paid = $4340 Answer
Similar Questions
(1) Find the amount to be paid if James borrowed a sum of $5000 at 6% simple interest for 8 years.
(2) How much loan did Cynthia borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $9142.5 to clear it?
(3) How much loan did Joseph borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6555 to clear it?
(4) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 9% simple interest?
(5) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 9% simple interest?
(6) Find the amount to be paid if Joseph borrowed a sum of $5700 at 7% simple interest for 8 years.
(7) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 5% simple interest?
(8) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 5% simple interest.
(9) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $9472 to clear the loan, then find the time period of the loan.
(10) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $7072 to clear the loan, then find the time period of the loan.