Question:
( 1 of 10 ) Find the amount to be paid if Robert borrowed a sum of $5100 at 5% simple interest for 7 years.
(A) 59
(B) 30.5
(C) 61
(D) 60
You selected
$5100
Correct Answer
$6885
Solution And Explanation
Solution
Given,
Principal (P) = $5100
Rate of Simple Interest (SI) = 5%
Time (t) = 7 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) = $5100 × 5% × 7
= $5100 ×5/100 × 7
= 5100 × 5 × 7/100
= 25500 × 7/100
= 178500/100
= $1785
Thus, Simple Interest = $1785
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 = $5100 + $1785
= $6885
Thus, Amount to be paid = $6885 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 = $5100
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 7 years
Thus, Amount (A)
= $5100 + ($5100 × 5% × 7)
= $5100 + ($5100 ×5/100 × 7)
= $5100 + (5100 × 5 × 7/100)
= $5100 + (25500 × 7/100)
= $5100 + (178500/100)
= $5100 + $1785 = $6885
Thus, Amount (A) to be paid = $6885 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 $5100, the simple interest in 1 year
= 5/100 × 5100
= 5 × 5100/100
= 25500/100 = $255
Thus, simple interest for 1 year = $255
Therefore, simple interest for 7 years
= Simple interest for 1 year × 7
= $255 × 7 = $1785
Thus, Simple Interest (SI) = $1785
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5100 + $1785
= $6885
Thus, Amount to be paid = $6885 Answer
Similar Questions
(1) How much loan did Betty borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7500 to clear it?
(2) Calculate the amount due if Jessica borrowed a sum of $3750 at 8% simple interest for 4 years.
(3) Calculate the amount due if Michael borrowed a sum of $3300 at 2% simple interest for 4 years.
(4) Calculate the amount due after 10 years if Jessica borrowed a sum of $5750 at a rate of 6% simple interest.
(5) Kimberly had to pay $5208 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(6) Find the amount to be paid if John borrowed a sum of $5200 at 10% simple interest for 7 years.
(7) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 2% simple interest?
(8) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 6% simple interest?
(9) How much loan did Donna borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7877.5 to clear it?
(10) In how much time a principal of $3200 will amount to $3840 at a simple interest of 4% per annum?