Question:
Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 6% simple interest.
Correct Answer
$9240
Solution And Explanation
Solution
Given,
Principal (P) = $6000
Rate of Simple Interest (SI) = 6%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $6000 × 6% × 9
= $6000 ×6/100 × 9
= 6000 × 6 × 9/100
= 36000 × 9/100
= 324000/100
= $3240
Thus, Simple Interest = $3240
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 = $6000 + $3240
= $9240
Thus, Amount to be paid = $9240 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 = $6000
Rate of Simple Interest (SI) or (R) = 6%
And, Time (t) = 9 years
Thus, Amount (A)
= $6000 + ($6000 × 6% × 9)
= $6000 + ($6000 ×6/100 × 9)
= $6000 + (6000 × 6 × 9/100)
= $6000 + (36000 × 9/100)
= $6000 + (324000/100)
= $6000 + $3240 = $9240
Thus, Amount (A) to be paid = $9240 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 6%
This, means, $6 per $100 per year
∵ For $100, the simple interest for 1 year = $6
∴ For $1, the simple interest for 1 year = 6/100
∴ For $6000, the simple interest in 1 year
= 6/100 × 6000
= 6 × 6000/100
= 36000/100 = $360
Thus, simple interest for 1 year = $360
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $360 × 9 = $3240
Thus, Simple Interest (SI) = $3240
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $6000 + $3240
= $9240
Thus, Amount to be paid = $9240 Answer
Similar Questions
(1) If Michael borrowed $3300 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.
(2) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 5% simple interest?
(3) What amount does John have to pay after 6 years if he takes a loan of $3200 at 9% simple interest?
(4) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 2% simple interest.
(5) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 2% simple interest.
(6) How much loan did Kenneth borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8050 to clear it?
(7) Calculate the amount due if Patricia borrowed a sum of $3150 at 5% simple interest for 4 years.
(8) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 7% simple interest.
(9) Find the amount to be paid if David borrowed a sum of $5400 at 2% simple interest for 8 years.
(10) Thomas had to pay $4370 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.