Simple Interest
Math MCQs

Question :    Find the amount to be paid if Joseph borrowed a sum of $5700 at 3% simple interest for 8 years.

Correct Answer  $7068

Solution & Explanation

Solution

Given,

Principal (P) = $5700

Rate of Simple Interest (SI) = 3%

Time (t) = 8 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5700 × 3% × 8

= $5700 ׳/₁₀₀ × 8

= ^{5700 × 3 × 8}/₁₀₀

= ^{17100 × 8}/₁₀₀

= ¹³⁶⁸⁰⁰/₁₀₀

= $1368

Thus, Simple Interest = $1368

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 = $5700 + $1368

= $7068

Thus, Amount to be paid = $7068 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 = $5700

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $5700 + ($5700 × 3% × 8)

= $5700 + ($5700 ׳/₁₀₀ × 8)

= $5700 + (^{5700 × 3 × 8}/₁₀₀)

= $5700 + (^{17100 × 8}/₁₀₀)

= $5700 + (¹³⁶⁸⁰⁰/₁₀₀)

= $5700 + $1368 = $7068

Thus, Amount (A) to be paid = $7068 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5700, the simple interest in 1 year

= ³/₁₀₀ × 5700

= ^{3 × 5700}/₁₀₀

= ¹⁷¹⁰⁰/₁₀₀ = $171

Thus, simple interest for 1 year = $171

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $171 × 8 = $1368

Thus, Simple Interest (SI) = $1368

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5700 + $1368

= $7068

Thus, Amount to be paid = $7068 Answer

Similar Questions

(1) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $6400 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 4% simple interest.

(3) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.

(4) Find the amount to be paid if Christopher borrowed a sum of $6000 at 9% simple interest for 7 years.

(5) Find the amount to be paid if Joseph borrowed a sum of $5700 at 5% simple interest for 7 years.

(6) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 4% simple interest?

(7) If Mark paid $4752 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(8) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 7% simple interest?

(9) If Donald paid $4860 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(10) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 9% simple interest.