Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 5% simple interest.

Correct Answer  $8850

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 5%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 10

= $5900 ×⁵/₁₀₀ × 10

= ^{5900 × 5 × 10}/₁₀₀

= ^{29500 × 10}/₁₀₀

= ²⁹⁵⁰⁰⁰/₁₀₀

= $2950

Thus, Simple Interest = $2950

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 + $2950

= $8850

Thus, Amount to be paid = $8850 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) = 5%

And, Time (t) = 10 years

Thus, Amount (A)

= $5900 + ($5900 × 5% × 10)

= $5900 + ($5900 ×⁵/₁₀₀ × 10)

= $5900 + (^{5900 × 5 × 10}/₁₀₀)

= $5900 + (^{29500 × 10}/₁₀₀)

= $5900 + (²⁹⁵⁰⁰⁰/₁₀₀)

= $5900 + $2950 = $8850

Thus, Amount (A) to be paid = $8850 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = ⁵/₁₀₀

∴ For $5900, the simple interest in 1 year

= ⁵/₁₀₀ × 5900

= ^{5 × 5900}/₁₀₀

= ²⁹⁵⁰⁰/₁₀₀ = $295

Thus, simple interest for 1 year = $295

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $295 × 10 = $2950

Thus, Simple Interest (SI) = $2950

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $2950

= $8850

Thus, Amount to be paid = $8850 Answer

Similar Questions

(1) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $12000 to clear the loan, then find the time period of the loan.

(2) Jennifer took a loan of $4500 at the rate of 6% simple interest per annum. If he paid an amount of $6660 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if Jennifer borrowed a sum of $3250 at 7% simple interest for 3 years.

(4) Calculate the amount due if John borrowed a sum of $3200 at 4% simple interest for 4 years.

(5) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $12920 to clear the loan, then find the time period of the loan.

(6) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 2% simple interest?

(7) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 7% simple interest for 8 years.

(8) Find the amount to be paid if Susan borrowed a sum of $5650 at 10% simple interest for 8 years.

(9) What amount will be due after 2 years if John borrowed a sum of $3100 at a 10% simple interest?

(10) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 10% simple interest?