Simple Interest
Math MCQs

Question :    Calculate the amount due if Joseph borrowed a sum of $3700 at 6% simple interest for 3 years.

Correct Answer  $4366

Solution & Explanation

Solution

Given,

Principal (P) = $3700

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) = $3700 × 6% × 3

= $3700 ×⁶/₁₀₀ × 3

= ^{3700 × 6 × 3}/₁₀₀

= ^{22200 × 3}/₁₀₀

= ⁶⁶⁶⁰⁰/₁₀₀

= $666

Thus, Simple Interest = $666

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 = $3700 + $666

= $4366

Thus, Amount to be paid = $4366 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 = $3700

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 3 years

Thus, Amount (A)

= $3700 + ($3700 × 6% × 3)

= $3700 + ($3700 ×⁶/₁₀₀ × 3)

= $3700 + (^{3700 × 6 × 3}/₁₀₀)

= $3700 + (^{22200 × 3}/₁₀₀)

= $3700 + (⁶⁶⁶⁰⁰/₁₀₀)

= $3700 + $666 = $4366

Thus, Amount (A) to be paid = $4366 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 $3700, the simple interest in 1 year

= ⁶/₁₀₀ × 3700

= ^{6 × 3700}/₁₀₀

= ²²²⁰⁰/₁₀₀ = $222

Thus, simple interest for 1 year = $222

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $222 × 3 = $666

Thus, Simple Interest (SI) = $666

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3700 + $666

= $4366

Thus, Amount to be paid = $4366 Answer

Similar Questions

(1) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $8662 to clear the loan, then find the time period of the loan.

(2) What amount does James have to pay after 5 years if he takes a loan of $3000 at 6% simple interest?

(3) Donna had to pay $5286.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(4) Charles took a loan of $5800 at the rate of 6% simple interest per annum. If he paid an amount of $7888 to clear the loan, then find the time period of the loan.

(5) Jessica took a loan of $5500 at the rate of 8% simple interest per annum. If he paid an amount of $8580 to clear the loan, then find the time period of the loan.

(6) Margaret took a loan of $6700 at the rate of 6% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.

(7) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 7% simple interest?

(8) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.

(9) William had to pay $3815 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $5440 to clear the loan, then find the time period of the loan.