Question:
What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 10% simple interest?
Correct Answer
$3660
Solution And Explanation
Solution
Given,
Principal (P) = $3050
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) = $3050 × 10% × 2
= $3050 ×10/100 × 2
= 3050 × 10 × 2/100
= 30500 × 2/100
= 61000/100
= $610
Thus, Simple Interest = $610
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 = $3050 + $610
= $3660
Thus, Amount to be paid = $3660 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 = $3050
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 2 years
Thus, Amount (A)
= $3050 + ($3050 × 10% × 2)
= $3050 + ($3050 ×10/100 × 2)
= $3050 + (3050 × 10 × 2/100)
= $3050 + (30500 × 2/100)
= $3050 + (61000/100)
= $3050 + $610 = $3660
Thus, Amount (A) to be paid = $3660 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 $3050, the simple interest in 1 year
= 10/100 × 3050
= 10 × 3050/100
= 30500/100 = $305
Thus, simple interest for 1 year = $305
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $305 × 2 = $610
Thus, Simple Interest (SI) = $610
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3050 + $610
= $3660
Thus, Amount to be paid = $3660 Answer
Similar Questions
(1) Calculate the amount due if John borrowed a sum of $3200 at 5% simple interest for 4 years.
(2) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 5% simple interest?
(3) What amount does Christopher have to pay after 5 years if he takes a loan of $4000 at 8% simple interest?
(4) Matthew took a loan of $6400 at the rate of 6% simple interest per annum. If he paid an amount of $9472 to clear the loan, then find the time period of the loan.
(5) Robert had to pay $3379 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(6) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 4% simple interest?
(7) Calculate the amount due if Sarah borrowed a sum of $3850 at 2% simple interest for 4 years.
(8) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 10% simple interest?
(9) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 5% simple interest for 8 years.
(10) Calculate the amount due if David borrowed a sum of $3400 at 7% simple interest for 3 years.