Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 6% simple interest.

Correct Answer  $9086

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 6%

Time (t) = 9 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) = $5900 × 6% × 9

= $5900 ×⁶/₁₀₀ × 9

= ^{5900 × 6 × 9}/₁₀₀

= ^{35400 × 9}/₁₀₀

= ³¹⁸⁶⁰⁰/₁₀₀

= $3186

Thus, Simple Interest = $3186

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 = $5900 + $3186

= $9086

Thus, Amount to be paid = $9086 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 = $5900

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

And, Time (t) = 9 years

Thus, Amount (A)

= $5900 + ($5900 × 6% × 9)

= $5900 + ($5900 ×⁶/₁₀₀ × 9)

= $5900 + (^{5900 × 6 × 9}/₁₀₀)

= $5900 + (^{35400 × 9}/₁₀₀)

= $5900 + (³¹⁸⁶⁰⁰/₁₀₀)

= $5900 + $3186 = $9086

Thus, Amount (A) to be paid = $9086 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 $5900, the simple interest in 1 year

= ⁶/₁₀₀ × 5900

= ^{6 × 5900}/₁₀₀

= ³⁵⁴⁰⁰/₁₀₀ = $354

Thus, simple interest for 1 year = $354

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $354 × 9 = $3186

Thus, Simple Interest (SI) = $3186

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $3186

= $9086

Thus, Amount to be paid = $9086 Answer

Similar Questions

(1) Robert took a loan of $4200 at the rate of 7% simple interest per annum. If he paid an amount of $6258 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 10% simple interest.

(3) If Charles paid $4368 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(4) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 5% simple interest?

(5) Patricia took a loan of $4300 at the rate of 6% simple interest per annum. If he paid an amount of $6106 to clear the loan, then find the time period of the loan.

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

(7) Find the amount to be paid if Richard borrowed a sum of $5600 at 7% simple interest for 7 years.

(8) Mary took a loan of $4100 at the rate of 10% simple interest per annum. If he paid an amount of $6970 to clear the loan, then find the time period of the loan.

(9) Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $13400 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due if Linda borrowed a sum of $3350 at 2% simple interest for 4 years.