Simple Interest
Math MCQs

Question :    Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 8 years.

Correct Answer  $9976

Solution & Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 9%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5800 × 9% × 8

= $5800 ×⁹/₁₀₀ × 8

= ^{5800 × 9 × 8}/₁₀₀

= ^{52200 × 8}/₁₀₀

= ⁴¹⁷⁶⁰⁰/₁₀₀

= $4176

Thus, Simple Interest = $4176

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 = $5800 + $4176

= $9976

Thus, Amount to be paid = $9976 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 = $5800

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 8 years

Thus, Amount (A)

= $5800 + ($5800 × 9% × 8)

= $5800 + ($5800 ×⁹/₁₀₀ × 8)

= $5800 + (^{5800 × 9 × 8}/₁₀₀)

= $5800 + (^{52200 × 8}/₁₀₀)

= $5800 + (⁴¹⁷⁶⁰⁰/₁₀₀)

= $5800 + $4176 = $9976

Thus, Amount (A) to be paid = $9976 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $5800, the simple interest in 1 year

= ⁹/₁₀₀ × 5800

= ^{9 × 5800}/₁₀₀

= ⁵²²⁰⁰/₁₀₀ = $522

Thus, simple interest for 1 year = $522

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $522 × 8 = $4176

Thus, Simple Interest (SI) = $4176

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $4176

= $9976

Thus, Amount to be paid = $9976 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 6% simple interest.

(2) Elizabeth had to pay $3864 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(3) What amount will be due after 2 years if William borrowed a sum of $3250 at a 5% simple interest?

(4) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 8% simple interest.

(5) How much loan did Ronald borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9000 to clear it?

(6) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 9% simple interest.

(7) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 10% simple interest.

(8) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 7% simple interest.

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

(10) Find the amount to be paid if Charles borrowed a sum of $5900 at 4% simple interest for 7 years.