Question:
What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 9% simple interest?
Correct Answer
$3599
Solution And Explanation
Solution
Given,
Principal (P) = $3050
Rate of Simple Interest (SI) = 9%
Time (t) = 2 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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 × 9% × 2
= $3050 ×9/100 × 2
= 3050 × 9 × 2/100
= 27450 × 2/100
= 54900/100
= $549
Thus, Simple Interest = $549
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 + $549
= $3599
Thus, Amount to be paid = $3599 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) = 9%
And, Time (t) = 2 years
Thus, Amount (A)
= $3050 + ($3050 × 9% × 2)
= $3050 + ($3050 ×9/100 × 2)
= $3050 + (3050 × 9 × 2/100)
= $3050 + (27450 × 2/100)
= $3050 + (54900/100)
= $3050 + $549 = $3599
Thus, Amount (A) to be paid = $3599 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 9%
This, means, $9 per $100 per year
∵ For $100, the simple interest for 1 year = $9
∴ For $1, the simple interest for 1 year = 9/100
∴ For $3050, the simple interest in 1 year
= 9/100 × 3050
= 9 × 3050/100
= 27450/100 = $274.5
Thus, simple interest for 1 year = $274.5
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $274.5 × 2 = $549
Thus, Simple Interest (SI) = $549
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3050 + $549
= $3599
Thus, Amount to be paid = $3599 Answer
Similar Questions
(1) Jennifer had to pay $3445 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(2) If Margaret paid $5220 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.
(3) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 10% simple interest?
(4) Calculate the amount due if John borrowed a sum of $3200 at 2% simple interest for 3 years.
(5) Calculate the amount due if Karen borrowed a sum of $3950 at 3% simple interest for 3 years.
(6) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 3% simple interest?
(7) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 7% simple interest.
(8) What amount does James have to pay after 6 years if he takes a loan of $3000 at 6% simple interest?
(9) Find the amount to be paid if Karen borrowed a sum of $5950 at 10% simple interest for 7 years.
(10) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $12127 to clear the loan, then find the time period of the loan.