Question:
What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 10% simple interest?
Correct Answer
$3960
Solution And Explanation
Solution
Given,
Principal (P) = $3300
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) = $3300 × 10% × 2
= $3300 ×10/100 × 2
= 3300 × 10 × 2/100
= 33000 × 2/100
= 66000/100
= $660
Thus, Simple Interest = $660
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 = $3300 + $660
= $3960
Thus, Amount to be paid = $3960 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 = $3300
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 2 years
Thus, Amount (A)
= $3300 + ($3300 × 10% × 2)
= $3300 + ($3300 ×10/100 × 2)
= $3300 + (3300 × 10 × 2/100)
= $3300 + (33000 × 2/100)
= $3300 + (66000/100)
= $3300 + $660 = $3960
Thus, Amount (A) to be paid = $3960 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 $3300, the simple interest in 1 year
= 10/100 × 3300
= 10 × 3300/100
= 33000/100 = $330
Thus, simple interest for 1 year = $330
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $330 × 2 = $660
Thus, Simple Interest (SI) = $660
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3300 + $660
= $3960
Thus, Amount to be paid = $3960 Answer
Similar Questions
(1) Nancy took a loan of $6300 at the rate of 10% simple interest per annum. If he paid an amount of $10710 to clear the loan, then find the time period of the loan.
(2) Barbara took a loan of $5100 at the rate of 7% simple interest per annum. If he paid an amount of $7956 to clear the loan, then find the time period of the loan.
(3) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 8% simple interest.
(4) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9760 to clear the loan, then find the time period of the loan.
(5) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 3% simple interest?
(6) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 10% simple interest.
(7) Andrew had to pay $5088 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(8) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 9% simple interest for 3 years.
(9) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $8470 to clear the loan, then find the time period of the loan.
(10) How much loan did Linda borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5885 to clear it?