Question:
Calculate the amount due if Sarah borrowed a sum of $3850 at 5% simple interest for 4 years.
Correct Answer
$4620
Solution And Explanation
Solution
Given,
Principal (P) = $3850
Rate of Simple Interest (SI) = 5%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3850 × 5% × 4
= $3850 ×5/100 × 4
= 3850 × 5 × 4/100
= 19250 × 4/100
= 77000/100
= $770
Thus, Simple Interest = $770
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 = $3850 + $770
= $4620
Thus, Amount to be paid = $4620 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 = $3850
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 4 years
Thus, Amount (A)
= $3850 + ($3850 × 5% × 4)
= $3850 + ($3850 ×5/100 × 4)
= $3850 + (3850 × 5 × 4/100)
= $3850 + (19250 × 4/100)
= $3850 + (77000/100)
= $3850 + $770 = $4620
Thus, Amount (A) to be paid = $4620 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 5%
This, means, $5 per $100 per year
∵ For $100, the simple interest for 1 year = $5
∴ For $1, the simple interest for 1 year = 5/100
∴ For $3850, the simple interest in 1 year
= 5/100 × 3850
= 5 × 3850/100
= 19250/100 = $192.5
Thus, simple interest for 1 year = $192.5
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $192.5 × 4 = $770
Thus, Simple Interest (SI) = $770
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3850 + $770
= $4620
Thus, Amount to be paid = $4620 Answer
Similar Questions
(1) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 5% simple interest?
(2) 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?
(3) Find the amount to be paid if Joseph borrowed a sum of $5700 at 5% simple interest for 7 years.
(4) In how much time a principal of $3150 will amount to $3528 at a simple interest of 4% per annum?
(5) Calculate the amount due if Patricia borrowed a sum of $3150 at 2% simple interest for 4 years.
(6) Thomas took a loan of $5600 at the rate of 8% simple interest per annum. If he paid an amount of $8736 to clear the loan, then find the time period of the loan.
(7) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 2% simple interest.
(8) Calculate the amount due if Barbara borrowed a sum of $3550 at 4% simple interest for 3 years.
(9) David had to pay $3706 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(10) How much loan did Jessica borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7187.5 to clear it?