Question:
Calculate the amount due if Susan borrowed a sum of $3650 at 3% simple interest for 3 years.
Correct Answer
$3978.5
Solution And Explanation
Solution
Given,
Principal (P) = $3650
Rate of Simple Interest (SI) = 3%
Time (t) = 3 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) = $3650 × 3% × 3
= $3650 ×3/100 × 3
= 3650 × 3 × 3/100
= 10950 × 3/100
= 32850/100
= $328.5
Thus, Simple Interest = $328.5
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 = $3650 + $328.5
= $3978.5
Thus, Amount to be paid = $3978.5 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 = $3650
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 3 years
Thus, Amount (A)
= $3650 + ($3650 × 3% × 3)
= $3650 + ($3650 ×3/100 × 3)
= $3650 + (3650 × 3 × 3/100)
= $3650 + (10950 × 3/100)
= $3650 + (32850/100)
= $3650 + $328.5 = $3978.5
Thus, Amount (A) to be paid = $3978.5 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 $3650, the simple interest in 1 year
= 3/100 × 3650
= 3 × 3650/100
= 10950/100 = $109.5
Thus, simple interest for 1 year = $109.5
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $109.5 × 3 = $328.5
Thus, Simple Interest (SI) = $328.5
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3650 + $328.5
= $3978.5
Thus, Amount to be paid = $3978.5 Answer
Similar Questions
(1) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 4% simple interest.
(2) Calculate the amount due if William borrowed a sum of $3500 at 9% simple interest for 3 years.
(3) Anthony took a loan of $6600 at the rate of 8% simple interest per annum. If he paid an amount of $10824 to clear the loan, then find the time period of the loan.
(4) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 6% simple interest?
(5) Michael took a loan of $4600 at the rate of 7% simple interest per annum. If he paid an amount of $7176 to clear the loan, then find the time period of the loan.
(6) Find the amount to be paid if Thomas borrowed a sum of $5800 at 4% simple interest for 7 years.
(7) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $10332 to clear the loan, then find the time period of the loan.
(8) Susan took a loan of $5300 at the rate of 6% simple interest per annum. If he paid an amount of $8162 to clear the loan, then find the time period of the loan.
(9) John took a loan of $4400 at the rate of 6% simple interest per annum. If he paid an amount of $5984 to clear the loan, then find the time period of the loan.
(10) Find the amount to be paid if Joseph borrowed a sum of $5700 at 10% simple interest for 7 years.