Simple Interest
Math MCQs

Question :  ( 1 of 10 )  Calculate the amount due if William borrowed a sum of $3500 at 6% simple interest for 3 years.

Correct Answer  $4130

Solution & Explanation

Solution

Given,

Principal (P) = $3500

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) = $3500 × 6% × 3

= $3500 ×⁶/₁₀₀ × 3

= ^{3500 × 6 × 3}/₁₀₀

= ^{21000 × 3}/₁₀₀

= ⁶³⁰⁰⁰/₁₀₀

= $630

Thus, Simple Interest = $630

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 = $3500 + $630

= $4130

Thus, Amount to be paid = $4130 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 = $3500

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

And, Time (t) = 3 years

Thus, Amount (A)

= $3500 + ($3500 × 6% × 3)

= $3500 + ($3500 ×⁶/₁₀₀ × 3)

= $3500 + (^{3500 × 6 × 3}/₁₀₀)

= $3500 + (^{21000 × 3}/₁₀₀)

= $3500 + (⁶³⁰⁰⁰/₁₀₀)

= $3500 + $630 = $4130

Thus, Amount (A) to be paid = $4130 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 $3500, the simple interest in 1 year

= ⁶/₁₀₀ × 3500

= ^{6 × 3500}/₁₀₀

= ²¹⁰⁰⁰/₁₀₀ = $210

Thus, simple interest for 1 year = $210

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $210 × 3 = $630

Thus, Simple Interest (SI) = $630

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3500 + $630

= $4130

Thus, Amount to be paid = $4130 Answer

Similar Questions

(1) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 8% simple interest.

(2) Margaret took a loan of $6700 at the rate of 8% simple interest per annum. If he paid an amount of $10452 to clear the loan, then find the time period of the loan.

(3) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $5712 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 3% simple interest.

(5) Calculate the amount due if Jessica borrowed a sum of $3750 at 4% simple interest for 4 years.

(6) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8000 to clear the loan, then find the time period of the loan.

(7) 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.

(8) What amount will be due after 2 years if John borrowed a sum of $3100 at a 7% simple interest?

(9) Elizabeth took a loan of $4900 at the rate of 10% simple interest per annum. If he paid an amount of $7840 to clear the loan, then find the time period of the loan.

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