Question:
Calculate the amount due if David borrowed a sum of $3400 at 6% simple interest for 3 years.
Correct Answer
$4012
Solution And Explanation
Solution
Given,
Principal (P) = $3400
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) = $3400 × 6% × 3
= $3400 ×6/100 × 3
= 3400 × 6 × 3/100
= 20400 × 3/100
= 61200/100
= $612
Thus, Simple Interest = $612
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 = $3400 + $612
= $4012
Thus, Amount to be paid = $4012 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 = $3400
Rate of Simple Interest (SI) or (R) = 6%
And, Time (t) = 3 years
Thus, Amount (A)
= $3400 + ($3400 × 6% × 3)
= $3400 + ($3400 ×6/100 × 3)
= $3400 + (3400 × 6 × 3/100)
= $3400 + (20400 × 3/100)
= $3400 + (61200/100)
= $3400 + $612 = $4012
Thus, Amount (A) to be paid = $4012 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 $3400, the simple interest in 1 year
= 6/100 × 3400
= 6 × 3400/100
= 20400/100 = $204
Thus, simple interest for 1 year = $204
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $204 × 3 = $612
Thus, Simple Interest (SI) = $612
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3400 + $612
= $4012
Thus, Amount to be paid = $4012 Answer
Similar Questions
(1) If Robert paid $3596 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(2) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 3% simple interest.
(3) Find the amount to be paid if Patricia borrowed a sum of $5150 at 8% simple interest for 8 years.
(4) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 9% simple interest?
(5) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 9% simple interest.
(6) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 6% simple interest.
(7) What amount will be due after 2 years if James borrowed a sum of $3000 at a 7% simple interest?
(8) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 7% simple interest?
(9) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 6% simple interest?
(10) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 7% simple interest.