Question:
Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 6% simple interest.
Correct Answer
$8470
Solution And Explanation
Solution
Given,
Principal (P) = $5500
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) = $5500 × 6% × 9
= $5500 ×6/100 × 9
= 5500 × 6 × 9/100
= 33000 × 9/100
= 297000/100
= $2970
Thus, Simple Interest = $2970
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 = $5500 + $2970
= $8470
Thus, Amount to be paid = $8470 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 = $5500
Rate of Simple Interest (SI) or (R) = 6%
And, Time (t) = 9 years
Thus, Amount (A)
= $5500 + ($5500 × 6% × 9)
= $5500 + ($5500 ×6/100 × 9)
= $5500 + (5500 × 6 × 9/100)
= $5500 + (33000 × 9/100)
= $5500 + (297000/100)
= $5500 + $2970 = $8470
Thus, Amount (A) to be paid = $8470 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 $5500, the simple interest in 1 year
= 6/100 × 5500
= 6 × 5500/100
= 33000/100 = $330
Thus, simple interest for 1 year = $330
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $330 × 9 = $2970
Thus, Simple Interest (SI) = $2970
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5500 + $2970
= $8470
Thus, Amount to be paid = $8470 Answer
Similar Questions
(1) In how much time a principal of $3100 will amount to $3410 at a simple interest of 2% per annum?
(2) If Jennifer borrowed $3250 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.
(3) Calculate the amount due if Linda borrowed a sum of $3350 at 5% simple interest for 4 years.
(4) What amount does William have to pay after 5 years if he takes a loan of $3500 at 8% simple interest?
(5) Matthew took a loan of $6400 at the rate of 10% simple interest per annum. If he paid an amount of $11520 to clear the loan, then find the time period of the loan.
(6) How much loan did Ronald borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9375 to clear it?
(7) How much loan did Thomas borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6960 to clear it?
(8) Donald took a loan of $7000 at the rate of 9% simple interest per annum. If he paid an amount of $10780 to clear the loan, then find the time period of the loan.
(9) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 2% simple interest.
(10) Calculate the amount due after 10 years if Michael borrowed a sum of $5300 at a rate of 9% simple interest.