Question:
What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 5% simple interest?
Correct Answer
$3850
Solution And Explanation
Solution
Given,
Principal (P) = $3500
Rate of Simple Interest (SI) = 5%
Time (t) = 2 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) = $3500 × 5% × 2
= $3500 ×5/100 × 2
= 3500 × 5 × 2/100
= 17500 × 2/100
= 35000/100
= $350
Thus, Simple Interest = $350
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 = $3500 + $350
= $3850
Thus, Amount to be paid = $3850 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 = $3500
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 2 years
Thus, Amount (A)
= $3500 + ($3500 × 5% × 2)
= $3500 + ($3500 ×5/100 × 2)
= $3500 + (3500 × 5 × 2/100)
= $3500 + (17500 × 2/100)
= $3500 + (35000/100)
= $3500 + $350 = $3850
Thus, Amount (A) to be paid = $3850 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 $3500, the simple interest in 1 year
= 5/100 × 3500
= 5 × 3500/100
= 17500/100 = $175
Thus, simple interest for 1 year = $175
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $175 × 2 = $350
Thus, Simple Interest (SI) = $350
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3500 + $350
= $3850
Thus, Amount to be paid = $3850 Answer
Similar Questions
(1) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 10% simple interest.
(2) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 8% simple interest.
(3) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 6% simple interest?
(4) Calculate the amount due if Patricia borrowed a sum of $3150 at 6% simple interest for 4 years.
(5) How much loan did Andrew borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8160 to clear it?
(6) Betty had to pay $4760 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(7) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 9% simple interest?
(8) Calculate the amount due if Barbara borrowed a sum of $3550 at 10% simple interest for 3 years.
(9) If William paid $3920 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.
(10) Find the amount to be paid if Joseph borrowed a sum of $5700 at 2% simple interest for 8 years.