Question:
Calculate the amount due if David borrowed a sum of $3400 at 4% simple interest for 4 years.
Correct Answer
$3944
Solution And Explanation
Solution
Given,
Principal (P) = $3400
Rate of Simple Interest (SI) = 4%
Time (t) = 4 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) = $3400 × 4% × 4
= $3400 ×4/100 × 4
= 3400 × 4 × 4/100
= 13600 × 4/100
= 54400/100
= $544
Thus, Simple Interest = $544
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 = $3400 + $544
= $3944
Thus, Amount to be paid = $3944 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 = $3400
Rate of Simple Interest (SI) or (R) = 4%
And, Time (t) = 4 years
Thus, Amount (A)
= $3400 + ($3400 × 4% × 4)
= $3400 + ($3400 ×4/100 × 4)
= $3400 + (3400 × 4 × 4/100)
= $3400 + (13600 × 4/100)
= $3400 + (54400/100)
= $3400 + $544 = $3944
Thus, Amount (A) to be paid = $3944 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 $3400, the simple interest in 1 year
= 4/100 × 3400
= 4 × 3400/100
= 13600/100 = $136
Thus, simple interest for 1 year = $136
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $136 × 4 = $544
Thus, Simple Interest (SI) = $544
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3400 + $544
= $3944
Thus, Amount to be paid = $3944 Answer
Similar Questions
(1) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 3% simple interest.
(2) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9028 to clear the loan, then find the time period of the loan.
(3) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 10% simple interest?
(4) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 4% simple interest?
(5) Lisa had to pay $4293 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(6) Daniel took a loan of $6200 at the rate of 7% simple interest per annum. If he paid an amount of $10106 to clear the loan, then find the time period of the loan.
(7) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $10318 to clear the loan, then find the time period of the loan.
(8) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 5% simple interest.
(9) Calculate the amount due if William borrowed a sum of $3500 at 7% simple interest for 4 years.
(10) How much loan did Timothy borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8880 to clear it?