Question:
Calculate the amount due if Karen borrowed a sum of $3950 at 3% simple interest for 4 years.
Correct Answer
$4424
Solution And Explanation
Solution
Given,
Principal (P) = $3950
Rate of Simple Interest (SI) = 3%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $3950 × 3% × 4
= $3950 ×3/100 × 4
= 3950 × 3 × 4/100
= 11850 × 4/100
= 47400/100
= $474
Thus, Simple Interest = $474
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 = $3950 + $474
= $4424
Thus, Amount to be paid = $4424 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 = $3950
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 4 years
Thus, Amount (A)
= $3950 + ($3950 × 3% × 4)
= $3950 + ($3950 ×3/100 × 4)
= $3950 + (3950 × 3 × 4/100)
= $3950 + (11850 × 4/100)
= $3950 + (47400/100)
= $3950 + $474 = $4424
Thus, Amount (A) to be paid = $4424 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 3%
This, means, $3 per $100 per year
∵ For $100, the simple interest for 1 year = $3
∴ For $1, the simple interest for 1 year = 3/100
∴ For $3950, the simple interest in 1 year
= 3/100 × 3950
= 3 × 3950/100
= 11850/100 = $118.5
Thus, simple interest for 1 year = $118.5
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $118.5 × 4 = $474
Thus, Simple Interest (SI) = $474
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3950 + $474
= $4424
Thus, Amount to be paid = $4424 Answer
Similar Questions
(1) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 4% simple interest?
(2) If Matthew paid $5040 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.
(3) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 4% simple interest?
(4) What amount will be due after 2 years if William borrowed a sum of $3250 at a 10% simple interest?
(5) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 4% simple interest?
(6) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 7% simple interest?
(7) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 8% simple interest?
(8) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 7% simple interest.
(9) If David paid $3944 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(10) How much loan did Ashley borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7532.5 to clear it?