Simple Interest
Math MCQs

Question :    Find the amount to be paid if Richard borrowed a sum of $5600 at 2% simple interest for 7 years.

Correct Answer  $6384

Solution & Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 2%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5600 × 2% × 7

= $5600 ײ/₁₀₀ × 7

= ^{5600 × 2 × 7}/₁₀₀

= ^{11200 × 7}/₁₀₀

= ⁷⁸⁴⁰⁰/₁₀₀

= $784

Thus, Simple Interest = $784

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 = $5600 + $784

= $6384

Thus, Amount to be paid = $6384 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 = $5600

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 7 years

Thus, Amount (A)

= $5600 + ($5600 × 2% × 7)

= $5600 + ($5600 ײ/₁₀₀ × 7)

= $5600 + (^{5600 × 2 × 7}/₁₀₀)

= $5600 + (^{11200 × 7}/₁₀₀)

= $5600 + (⁷⁸⁴⁰⁰/₁₀₀)

= $5600 + $784 = $6384

Thus, Amount (A) to be paid = $6384 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $5600, the simple interest in 1 year

= ²/₁₀₀ × 5600

= ^{2 × 5600}/₁₀₀

= ¹¹²⁰⁰/₁₀₀ = $112

Thus, simple interest for 1 year = $112

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $112 × 7 = $784

Thus, Simple Interest (SI) = $784

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $784

= $6384

Thus, Amount to be paid = $6384 Answer

Similar Questions

(1) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $12127 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if Richard borrowed a sum of $5600 at 7% simple interest for 8 years.

(3) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $12000 to clear the loan, then find the time period of the loan.

(4) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6560 to clear the loan, then find the time period of the loan.

(5) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 4% simple interest?

(6) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 9% simple interest.

(7) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 9% simple interest?

(8) If Patricia borrowed $3150 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(9) Thomas had to pay $4256 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(10) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 8 years.