Question:
What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 10% simple interest?
Correct Answer
$5680
Solution And Explanation
Solution
Given,
Principal (P) = $3550
Rate of Simple Interest (SI) = 10%
Time (t) = 6 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) = $3550 × 10% × 6
= $3550 ×10/100 × 6
= 3550 × 10 × 6/100
= 35500 × 6/100
= 213000/100
= $2130
Thus, Simple Interest = $2130
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 = $3550 + $2130
= $5680
Thus, Amount to be paid = $5680 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 = $3550
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 6 years
Thus, Amount (A)
= $3550 + ($3550 × 10% × 6)
= $3550 + ($3550 ×10/100 × 6)
= $3550 + (3550 × 10 × 6/100)
= $3550 + (35500 × 6/100)
= $3550 + (213000/100)
= $3550 + $2130 = $5680
Thus, Amount (A) to be paid = $5680 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 $3550, the simple interest in 1 year
= 10/100 × 3550
= 10 × 3550/100
= 35500/100 = $355
Thus, simple interest for 1 year = $355
Therefore, simple interest for 6 years
= Simple interest for 1 year × 6
= $355 × 6 = $2130
Thus, Simple Interest (SI) = $2130
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3550 + $2130
= $5680
Thus, Amount to be paid = $5680 Answer
Similar Questions
(1) In how much time a principal of $3100 will amount to $3286 at a simple interest of 2% per annum?
(2) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 6% simple interest.
(3) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 8% simple interest.
(4) In how much time a principal of $3100 will amount to $3565 at a simple interest of 3% per annum?
(5) If Joseph borrowed $3700 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.
(6) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 9% simple interest?
(7) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 2% simple interest?
(8) Charles took a loan of $5800 at the rate of 9% simple interest per annum. If he paid an amount of $8932 to clear the loan, then find the time period of the loan.
(9) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 10% simple interest.
(10) Find the amount to be paid if Jessica borrowed a sum of $5750 at 8% simple interest for 7 years.