Simple Interest
Math MCQs

Question :    What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 6% simple interest?

Correct Answer  $4095

Solution & Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 6%

Time (t) = 5 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) = $3150 × 6% × 5

= $3150 ×⁶/₁₀₀ × 5

= ^{3150 × 6 × 5}/₁₀₀

= ^{18900 × 5}/₁₀₀

= ⁹⁴⁵⁰⁰/₁₀₀

= $945

Thus, Simple Interest = $945

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 = $3150 + $945

= $4095

Thus, Amount to be paid = $4095 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 = $3150

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

And, Time (t) = 5 years

Thus, Amount (A)

= $3150 + ($3150 × 6% × 5)

= $3150 + ($3150 ×⁶/₁₀₀ × 5)

= $3150 + (^{3150 × 6 × 5}/₁₀₀)

= $3150 + (^{18900 × 5}/₁₀₀)

= $3150 + (⁹⁴⁵⁰⁰/₁₀₀)

= $3150 + $945 = $4095

Thus, Amount (A) to be paid = $4095 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 $3150, the simple interest in 1 year

= ⁶/₁₀₀ × 3150

= ^{6 × 3150}/₁₀₀

= ¹⁸⁹⁰⁰/₁₀₀ = $189

Thus, simple interest for 1 year = $189

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $189 × 5 = $945

Thus, Simple Interest (SI) = $945

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $945

= $4095

Thus, Amount to be paid = $4095 Answer

Similar Questions

(1) Calculate the amount due if Linda borrowed a sum of $3350 at 5% simple interest for 4 years.

(2) Find the amount to be paid if James borrowed a sum of $5000 at 2% simple interest for 8 years.

(3) Steven had to pay $4876 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

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

(5) Find the amount to be paid if Susan borrowed a sum of $5650 at 10% simple interest for 7 years.

(6) Calculate the amount due if Jessica borrowed a sum of $3750 at 8% simple interest for 4 years.

(7) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $10106 to clear the loan, then find the time period of the loan.

(8) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 8% simple interest?

(9) Find the amount to be paid if Jessica borrowed a sum of $5750 at 8% simple interest for 8 years.

(10) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $5680 to clear the loan, then find the time period of the loan.