Question:
Calculate the amount due if Mary borrowed a sum of $3050 at 6% simple interest for 3 years.
Correct Answer
$3599
Solution And Explanation
Solution
Given,
Principal (P) = $3050
Rate of Simple Interest (SI) = 6%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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 × 6% × 3
= $3050 ×6/100 × 3
= 3050 × 6 × 3/100
= 18300 × 3/100
= 54900/100
= $549
Thus, Simple Interest = $549
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 + $549
= $3599
Thus, Amount to be paid = $3599 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) = 6%
And, Time (t) = 3 years
Thus, Amount (A)
= $3050 + ($3050 × 6% × 3)
= $3050 + ($3050 ×6/100 × 3)
= $3050 + (3050 × 6 × 3/100)
= $3050 + (18300 × 3/100)
= $3050 + (54900/100)
= $3050 + $549 = $3599
Thus, Amount (A) to be paid = $3599 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 6%
This, means, $6 per $100 per year
∵ For $100, the simple interest for 1 year = $6
∴ For $1, the simple interest for 1 year = 6/100
∴ For $3050, the simple interest in 1 year
= 6/100 × 3050
= 6 × 3050/100
= 18300/100 = $183
Thus, simple interest for 1 year = $183
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $183 × 3 = $549
Thus, Simple Interest (SI) = $549
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3050 + $549
= $3599
Thus, Amount to be paid = $3599 Answer
Similar Questions
(1) Jennifer took a loan of $4500 at the rate of 7% simple interest per annum. If he paid an amount of $7335 to clear the loan, then find the time period of the loan.
(2) Mary took a loan of $4100 at the rate of 8% simple interest per annum. If he paid an amount of $6068 to clear the loan, then find the time period of the loan.
(3) How much loan did Kevin borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8165 to clear it?
(4) Find the amount to be paid if Charles borrowed a sum of $5900 at 10% simple interest for 7 years.
(5) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 6% simple interest?
(6) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 4% simple interest?
(7) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 4% simple interest for 7 years.
(8) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 9% simple interest.
(9) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 8% simple interest?
(10) Find the amount to be paid if Sarah borrowed a sum of $5850 at 7% simple interest for 8 years.