Question:
What amount will be due after 2 years if William borrowed a sum of $3250 at a 10% simple interest?
Correct Answer
$3900
Solution And Explanation
Solution
Given,
Principal (P) = $3250
Rate of Simple Interest (SI) = 10%
Time (t) = 2 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3250 × 10% × 2
= $3250 ×10/100 × 2
= 3250 × 10 × 2/100
= 32500 × 2/100
= 65000/100
= $650
Thus, Simple Interest = $650
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 = $3250 + $650
= $3900
Thus, Amount to be paid = $3900 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 = $3250
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 2 years
Thus, Amount (A)
= $3250 + ($3250 × 10% × 2)
= $3250 + ($3250 ×10/100 × 2)
= $3250 + (3250 × 10 × 2/100)
= $3250 + (32500 × 2/100)
= $3250 + (65000/100)
= $3250 + $650 = $3900
Thus, Amount (A) to be paid = $3900 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 10%
This, means, $10 per $100 per year
∵ For $100, the simple interest for 1 year = $10
∴ For $1, the simple interest for 1 year = 10/100
∴ For $3250, the simple interest in 1 year
= 10/100 × 3250
= 10 × 3250/100
= 32500/100 = $325
Thus, simple interest for 1 year = $325
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $325 × 2 = $650
Thus, Simple Interest (SI) = $650
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3250 + $650
= $3900
Thus, Amount to be paid = $3900 Answer
Similar Questions
(1) Find the amount to be paid if David borrowed a sum of $5400 at 5% simple interest for 8 years.
(2) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 9% simple interest?
(3) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 4% simple interest.
(4) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $9520 to clear the loan, then find the time period of the loan.
(5) Thomas had to pay $4028 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(6) Sandra took a loan of $6900 at the rate of 8% simple interest per annum. If he paid an amount of $10212 to clear the loan, then find the time period of the loan.
(7) Paul had to pay $5405 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.
(8) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 3% simple interest.
(9) Barbara took a loan of $5100 at the rate of 10% simple interest per annum. If he paid an amount of $9180 to clear the loan, then find the time period of the loan.
(10) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11222 to clear the loan, then find the time period of the loan.