Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 6% simple interest.

Correct Answer  $9440

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 6%

Time (t) = 10 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% × 10

= $5900 ×⁶/₁₀₀ × 10

= ^{5900 × 6 × 10}/₁₀₀

= ^{35400 × 10}/₁₀₀

= ³⁵⁴⁰⁰⁰/₁₀₀

= $3540

Thus, Simple Interest = $3540

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 + $3540

= $9440

Thus, Amount to be paid = $9440 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) = 10 years

Thus, Amount (A)

= $5900 + ($5900 × 6% × 10)

= $5900 + ($5900 ×⁶/₁₀₀ × 10)

= $5900 + (^{5900 × 6 × 10}/₁₀₀)

= $5900 + (^{35400 × 10}/₁₀₀)

= $5900 + (³⁵⁴⁰⁰⁰/₁₀₀)

= $5900 + $3540 = $9440

Thus, Amount (A) to be paid = $9440 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 10 years

= Simple interest for 1 year × 10

= $354 × 10 = $3540

Thus, Simple Interest (SI) = $3540

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $3540

= $9440

Thus, Amount to be paid = $9440 Answer

Similar Questions

(1) Paul had to pay $5123 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(2) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 4% simple interest?

(3) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9984 to clear the loan, then find the time period of the loan.

(4) Donald took a loan of $7000 at the rate of 6% simple interest per annum. If he paid an amount of $10780 to clear the loan, then find the time period of the loan.

(5) Donald took a loan of $7000 at the rate of 6% simple interest per annum. If he paid an amount of $10360 to clear the loan, then find the time period of the loan.

(6) If Margaret paid $4872 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(7) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $9880 to clear the loan, then find the time period of the loan.

(8) What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 7% simple interest?

(9) Kimberly had to pay $4929 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(10) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 5% simple interest.