Question:
Find the amount to be paid if John borrowed a sum of $5200 at 7% simple interest for 8 years.
Correct Answer
$8112
Solution And Explanation
Solution
Given,
Principal (P) = $5200
Rate of Simple Interest (SI) = 7%
Time (t) = 8 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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) = $5200 × 7% × 8
= $5200 ×7/100 × 8
= 5200 × 7 × 8/100
= 36400 × 8/100
= 291200/100
= $2912
Thus, Simple Interest = $2912
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 = $5200 + $2912
= $8112
Thus, Amount to be paid = $8112 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 = $5200
Rate of Simple Interest (SI) or (R) = 7%
And, Time (t) = 8 years
Thus, Amount (A)
= $5200 + ($5200 × 7% × 8)
= $5200 + ($5200 ×7/100 × 8)
= $5200 + (5200 × 7 × 8/100)
= $5200 + (36400 × 8/100)
= $5200 + (291200/100)
= $5200 + $2912 = $8112
Thus, Amount (A) to be paid = $8112 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 7%
This, means, $7 per $100 per year
∵ For $100, the simple interest for 1 year = $7
∴ For $1, the simple interest for 1 year = 7/100
∴ For $5200, the simple interest in 1 year
= 7/100 × 5200
= 7 × 5200/100
= 36400/100 = $364
Thus, simple interest for 1 year = $364
Therefore, simple interest for 8 years
= Simple interest for 1 year × 8
= $364 × 8 = $2912
Thus, Simple Interest (SI) = $2912
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5200 + $2912
= $8112
Thus, Amount to be paid = $8112 Answer
Similar Questions
(1) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $10136 to clear the loan, then find the time period of the loan.
(2) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9536 to clear the loan, then find the time period of the loan.
(3) How much loan did Sandra borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7095 to clear it?
(4) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 8% simple interest?
(5) Find the amount to be paid if Linda borrowed a sum of $5350 at 7% simple interest for 8 years.
(6) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $7912 to clear the loan, then find the time period of the loan.
(7) In how much time a principal of $3000 will amount to $3240 at a simple interest of 4% per annum?
(8) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 9% simple interest.
(9) In how much time a principal of $3000 will amount to $3450 at a simple interest of 3% per annum?
(10) Margaret took a loan of $6700 at the rate of 6% simple interest per annum. If he paid an amount of $9112 to clear the loan, then find the time period of the loan.