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) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 10% simple interest.
(2) In how much time a principal of $3150 will amount to $3937.5 at a simple interest of 5% per annum?
(3) Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 8 years.
(4) Calculate the amount due if John borrowed a sum of $3200 at 6% simple interest for 4 years.
(5) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 8% simple interest?
(6) Kenneth had to pay $5300 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(7) How much loan did Lisa borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7260 to clear it?
(8) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $6364 to clear the loan, then find the time period of the loan.
(9) Find the amount to be paid if Thomas borrowed a sum of $5800 at 10% simple interest for 7 years.
(10) How much loan did George borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8030 to clear it?