Question:
Calculate the amount due if Thomas borrowed a sum of $3800 at 10% simple interest for 3 years.
Correct Answer
$4940
Solution And Explanation
Solution
Given,
Principal (P) = $3800
Rate of Simple Interest (SI) = 10%
Time (t) = 3 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) = $3800 × 10% × 3
= $3800 ×10/100 × 3
= 3800 × 10 × 3/100
= 38000 × 3/100
= 114000/100
= $1140
Thus, Simple Interest = $1140
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 = $3800 + $1140
= $4940
Thus, Amount to be paid = $4940 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 = $3800
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 3 years
Thus, Amount (A)
= $3800 + ($3800 × 10% × 3)
= $3800 + ($3800 ×10/100 × 3)
= $3800 + (3800 × 10 × 3/100)
= $3800 + (38000 × 3/100)
= $3800 + (114000/100)
= $3800 + $1140 = $4940
Thus, Amount (A) to be paid = $4940 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 $3800, the simple interest in 1 year
= 10/100 × 3800
= 10 × 3800/100
= 38000/100 = $380
Thus, simple interest for 1 year = $380
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $380 × 3 = $1140
Thus, Simple Interest (SI) = $1140
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3800 + $1140
= $4940
Thus, Amount to be paid = $4940 Answer
Similar Questions
(1) What amount will be due after 2 years if David borrowed a sum of $3200 at a 10% simple interest?
(2) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 9% simple interest.
(3) What amount does William have to pay after 5 years if he takes a loan of $3500 at 10% simple interest?
(4) Sandra had to pay $4984 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(5) Ashley had to pay $5096 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(6) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 5% simple interest?
(7) Calculate the amount due if Jessica borrowed a sum of $3750 at 3% simple interest for 3 years.
(8) Find the amount to be paid if Joseph borrowed a sum of $5700 at 8% simple interest for 8 years.
(9) If Kenneth paid $5800 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(10) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 4% simple interest?