Question:
Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 2% simple interest.
Correct Answer
$6018
Solution And Explanation
Solution
Given,
Principal (P) = $5100
Rate of Simple Interest (SI) = 2%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5100 × 2% × 9
= $5100 ×2/100 × 9
= 5100 × 2 × 9/100
= 10200 × 9/100
= 91800/100
= $918
Thus, Simple Interest = $918
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 = $5100 + $918
= $6018
Thus, Amount to be paid = $6018 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 = $5100
Rate of Simple Interest (SI) or (R) = 2%
And, Time (t) = 9 years
Thus, Amount (A)
= $5100 + ($5100 × 2% × 9)
= $5100 + ($5100 ×2/100 × 9)
= $5100 + (5100 × 2 × 9/100)
= $5100 + (10200 × 9/100)
= $5100 + (91800/100)
= $5100 + $918 = $6018
Thus, Amount (A) to be paid = $6018 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 2%
This, means, $2 per $100 per year
∵ For $100, the simple interest for 1 year = $2
∴ For $1, the simple interest for 1 year = 2/100
∴ For $5100, the simple interest in 1 year
= 2/100 × 5100
= 2 × 5100/100
= 10200/100 = $102
Thus, simple interest for 1 year = $102
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $102 × 9 = $918
Thus, Simple Interest (SI) = $918
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5100 + $918
= $6018
Thus, Amount to be paid = $6018 Answer
Similar Questions
(1) Find the amount to be paid if Robert borrowed a sum of $5100 at 9% simple interest for 8 years.
(2) Find the amount to be paid if Karen borrowed a sum of $5950 at 8% simple interest for 8 years.
(3) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $11560 to clear the loan, then find the time period of the loan.
(4) If Susan paid $4234 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(5) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $7602 to clear the loan, then find the time period of the loan.
(6) John took a loan of $4400 at the rate of 8% simple interest per annum. If he paid an amount of $6864 to clear the loan, then find the time period of the loan.
(7) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 6% simple interest?
(8) Charles had to pay $4251 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(9) Susan took a loan of $5300 at the rate of 7% simple interest per annum. If he paid an amount of $8639 to clear the loan, then find the time period of the loan.
(10) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $8320 to clear the loan, then find the time period of the loan.