Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 7% simple interest.

Correct Answer  $9617

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 7%

Time (t) = 9 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) = $5900 × 7% × 9

= $5900 ×⁷/₁₀₀ × 9

= ^{5900 × 7 × 9}/₁₀₀

= ^{41300 × 9}/₁₀₀

= ³⁷¹⁷⁰⁰/₁₀₀

= $3717

Thus, Simple Interest = $3717

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 = $5900 + $3717

= $9617

Thus, Amount to be paid = $9617 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 = $5900

Rate of Simple Interest (SI) or (R) = 7%

And, Time (t) = 9 years

Thus, Amount (A)

= $5900 + ($5900 × 7% × 9)

= $5900 + ($5900 ×⁷/₁₀₀ × 9)

= $5900 + (^{5900 × 7 × 9}/₁₀₀)

= $5900 + (^{41300 × 9}/₁₀₀)

= $5900 + (³⁷¹⁷⁰⁰/₁₀₀)

= $5900 + $3717 = $9617

Thus, Amount (A) to be paid = $9617 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 $5900, the simple interest in 1 year

= ⁷/₁₀₀ × 5900

= ^{7 × 5900}/₁₀₀

= ⁴¹³⁰⁰/₁₀₀ = $413

Thus, simple interest for 1 year = $413

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $413 × 9 = $3717

Thus, Simple Interest (SI) = $3717

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $3717

= $9617

Thus, Amount to be paid = $9617 Answer

Similar Questions

(1) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 10% simple interest for 7 years.

(2) How much loan did Ryan borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9480 to clear it?

(3) Calculate the amount due if James borrowed a sum of $3000 at 7% simple interest for 3 years.

(4) Joseph had to pay $4144 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(5) Find the amount to be paid if James borrowed a sum of $5000 at 2% simple interest for 7 years.

(6) If Nancy paid $4482 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(7) What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 7% simple interest?

(8) Lisa took a loan of $6100 at the rate of 10% simple interest per annum. If he paid an amount of $10980 to clear the loan, then find the time period of the loan.

(9) How much loan did Linda borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $6687.5 to clear it?

(10) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 6% simple interest?