Question:
Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.
Correct Answer
$6868
Solution And Explanation
Solution
Given,
Principal (P) = $5050
Rate of Simple Interest (SI) = 4%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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 × 4% × 9
= $5050 ×4/100 × 9
= 5050 × 4 × 9/100
= 20200 × 9/100
= 181800/100
= $1818
Thus, Simple Interest = $1818
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 + $1818
= $6868
Thus, Amount to be paid = $6868 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) = 4%
And, Time (t) = 9 years
Thus, Amount (A)
= $5050 + ($5050 × 4% × 9)
= $5050 + ($5050 ×4/100 × 9)
= $5050 + (5050 × 4 × 9/100)
= $5050 + (20200 × 9/100)
= $5050 + (181800/100)
= $5050 + $1818 = $6868
Thus, Amount (A) to be paid = $6868 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 4%
This, means, $4 per $100 per year
∵ For $100, the simple interest for 1 year = $4
∴ For $1, the simple interest for 1 year = 4/100
∴ For $5050, the simple interest in 1 year
= 4/100 × 5050
= 4 × 5050/100
= 20200/100 = $202
Thus, simple interest for 1 year = $202
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $202 × 9 = $1818
Thus, Simple Interest (SI) = $1818
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5050 + $1818
= $6868
Thus, Amount to be paid = $6868 Answer
Similar Questions
(1) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 10% simple interest?
(2) Calculate the amount due if Susan borrowed a sum of $3650 at 8% simple interest for 3 years.
(3) In how much time a principal of $3200 will amount to $3840 at a simple interest of 4% per annum?
(4) Find the amount to be paid if Karen borrowed a sum of $5950 at 6% simple interest for 8 years.
(5) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $6400 to clear the loan, then find the time period of the loan.
(6) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 8% simple interest.
(7) Calculate the amount due if Richard borrowed a sum of $3600 at 8% simple interest for 4 years.
(8) What amount will be due after 2 years if Joseph borrowed a sum of $3350 at a 6% simple interest?
(9) Calculate the amount due if Patricia borrowed a sum of $3150 at 2% simple interest for 3 years.
(10) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $9324 to clear the loan, then find the time period of the loan.