Question:
Calculate the amount due if Mary borrowed a sum of $3050 at 10% simple interest for 3 years.
Correct Answer
$3965
Solution And Explanation
Solution
Given,
Principal (P) = $3050
Rate of Simple Interest (SI) = 10%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3050 × 10% × 3
= $3050 ×10/100 × 3
= 3050 × 10 × 3/100
= 30500 × 3/100
= 91500/100
= $915
Thus, Simple Interest = $915
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 = $3050 + $915
= $3965
Thus, Amount to be paid = $3965 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 = $3050
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 3 years
Thus, Amount (A)
= $3050 + ($3050 × 10% × 3)
= $3050 + ($3050 ×10/100 × 3)
= $3050 + (3050 × 10 × 3/100)
= $3050 + (30500 × 3/100)
= $3050 + (91500/100)
= $3050 + $915 = $3965
Thus, Amount (A) to be paid = $3965 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 10%
This, means, $10 per $100 per year
∵ For $100, the simple interest for 1 year = $10
∴ For $1, the simple interest for 1 year = 10/100
∴ For $3050, the simple interest in 1 year
= 10/100 × 3050
= 10 × 3050/100
= 30500/100 = $305
Thus, simple interest for 1 year = $305
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $305 × 3 = $915
Thus, Simple Interest (SI) = $915
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3050 + $915
= $3965
Thus, Amount to be paid = $3965 Answer
Similar Questions
(1) What amount will be due after 2 years if William borrowed a sum of $3250 at a 7% simple interest?
(2) If Christopher paid $4480 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.
(3) Find the amount to be paid if Susan borrowed a sum of $5650 at 3% simple interest for 7 years.
(4) Calculate the amount due if Linda borrowed a sum of $3350 at 10% simple interest for 3 years.
(5) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 5% simple interest?
(6) Jessica took a loan of $5500 at the rate of 7% simple interest per annum. If he paid an amount of $8580 to clear the loan, then find the time period of the loan.
(7) If Nancy paid $4814 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(8) Find the amount to be paid if Linda borrowed a sum of $5350 at 3% simple interest for 7 years.
(9) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 3% simple interest?
(10) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 10% simple interest.