Simple Interest
Math MCQs

Question :    Calculate the amount due if Barbara borrowed a sum of $3550 at 4% simple interest for 4 years.

Correct Answer  $4118

Solution & Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 4%

Time (t) = 4 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $3550 × 4% × 4

= $3550 ×⁴/₁₀₀ × 4

= ^{3550 × 4 × 4}/₁₀₀

= ^{14200 × 4}/₁₀₀

= ⁵⁶⁸⁰⁰/₁₀₀

= $568

Thus, Simple Interest = $568

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 = $3550 + $568

= $4118

Thus, Amount to be paid = $4118 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 = $3550

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 4 years

Thus, Amount (A)

= $3550 + ($3550 × 4% × 4)

= $3550 + ($3550 ×⁴/₁₀₀ × 4)

= $3550 + (^{3550 × 4 × 4}/₁₀₀)

= $3550 + (^{14200 × 4}/₁₀₀)

= $3550 + (⁵⁶⁸⁰⁰/₁₀₀)

= $3550 + $568 = $4118

Thus, Amount (A) to be paid = $4118 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = ⁴/₁₀₀

∴ For $3550, the simple interest in 1 year

= ⁴/₁₀₀ × 3550

= ^{4 × 3550}/₁₀₀

= ¹⁴²⁰⁰/₁₀₀ = $142

Thus, simple interest for 1 year = $142

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $142 × 4 = $568

Thus, Simple Interest (SI) = $568

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $568

= $4118

Thus, Amount to be paid = $4118 Answer

Similar Questions

(1) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 2% simple interest?

(2) Calculate the amount due if Jessica borrowed a sum of $3750 at 9% simple interest for 4 years.

(3) If Jessica borrowed $3750 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(4) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 5% simple interest?

(5) What amount does James have to pay after 6 years if he takes a loan of $3000 at 10% simple interest?

(6) Find the amount to be paid if Jessica borrowed a sum of $5750 at 5% simple interest for 7 years.

(7) Christopher had to pay $4240 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(8) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 2% simple interest for 8 years.

(9) Find the amount to be paid if Karen borrowed a sum of $5950 at 9% simple interest for 7 years.

(10) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8312.5 to clear it?