Question:
Find the amount to be paid if Mary borrowed a sum of $5050 at 5% simple interest for 7 years.
Correct Answer
$6817.5
Solution And Explanation
Solution
Given,
Principal (P) = $5050
Rate of Simple Interest (SI) = 5%
Time (t) = 7 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $5050 × 5% × 7
= $5050 ×5/100 × 7
= 5050 × 5 × 7/100
= 25250 × 7/100
= 176750/100
= $1767.5
Thus, Simple Interest = $1767.5
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 = $5050 + $1767.5
= $6817.5
Thus, Amount to be paid = $6817.5 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 = $5050
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 7 years
Thus, Amount (A)
= $5050 + ($5050 × 5% × 7)
= $5050 + ($5050 ×5/100 × 7)
= $5050 + (5050 × 5 × 7/100)
= $5050 + (25250 × 7/100)
= $5050 + (176750/100)
= $5050 + $1767.5 = $6817.5
Thus, Amount (A) to be paid = $6817.5 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 5%
This, means, $5 per $100 per year
∵ For $100, the simple interest for 1 year = $5
∴ For $1, the simple interest for 1 year = 5/100
∴ For $5050, the simple interest in 1 year
= 5/100 × 5050
= 5 × 5050/100
= 25250/100 = $252.5
Thus, simple interest for 1 year = $252.5
Therefore, simple interest for 7 years
= Simple interest for 1 year × 7
= $252.5 × 7 = $1767.5
Thus, Simple Interest (SI) = $1767.5
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5050 + $1767.5
= $6817.5
Thus, Amount to be paid = $6817.5 Answer
Similar Questions
(1) If Emily paid $5130 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(2) How much loan did Deborah borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8567.5 to clear it?
(3) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 4% simple interest for 3 years.
(4) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 5% simple interest.
(5) Calculate the amount due if Joseph borrowed a sum of $3700 at 4% simple interest for 4 years.
(6) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 9% simple interest?
(7) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 5% simple interest.
(8) Calculate the amount due if Jennifer borrowed a sum of $3250 at 9% simple interest for 3 years.
(9) Find the amount to be paid if Karen borrowed a sum of $5950 at 8% simple interest for 7 years.
(10) John took a loan of $4400 at the rate of 7% simple interest per annum. If he paid an amount of $7480 to clear the loan, then find the time period of the loan.