Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 2% simple interest.

Correct Answer  $6840

Solution & Explanation

Solution

Given,

Principal (P) = $5700

Rate of Simple Interest (SI) = 2%

Time (t) = 10 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) = $5700 × 2% × 10

= $5700 ײ/₁₀₀ × 10

= ^{5700 × 2 × 10}/₁₀₀

= ^{11400 × 10}/₁₀₀

= ¹¹⁴⁰⁰⁰/₁₀₀

= $1140

Thus, Simple Interest = $1140

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 = $5700 + $1140

= $6840

Thus, Amount to be paid = $6840 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 = $5700

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5700 + ($5700 × 2% × 10)

= $5700 + ($5700 ײ/₁₀₀ × 10)

= $5700 + (^{5700 × 2 × 10}/₁₀₀)

= $5700 + (^{11400 × 10}/₁₀₀)

= $5700 + (¹¹⁴⁰⁰⁰/₁₀₀)

= $5700 + $1140 = $6840

Thus, Amount (A) to be paid = $6840 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 $5700, the simple interest in 1 year

= ²/₁₀₀ × 5700

= ^{2 × 5700}/₁₀₀

= ¹¹⁴⁰⁰/₁₀₀ = $114

Thus, simple interest for 1 year = $114

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $114 × 10 = $1140

Thus, Simple Interest (SI) = $1140

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5700 + $1140

= $6840

Thus, Amount to be paid = $6840 Answer

Similar Questions

(1) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 10% simple interest for 7 years.

(2) Richard had to pay $4140 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 9% simple interest?

(4) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 8% simple interest.

(5) How much loan did Robert borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6120 to clear it?

(6) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 2% simple interest?

(7) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 9% simple interest?

(8) Calculate the amount due if Thomas borrowed a sum of $3800 at 8% simple interest for 4 years.

(9) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 10% simple interest.

(10) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 7% simple interest for 7 years.