Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 2% simple interest.

Correct Answer  $7200

Solution & Explanation

Solution

Given,

Principal (P) = $6000

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) = $6000 × 2% × 10

= $6000 ײ/₁₀₀ × 10

= ^{6000 × 2 × 10}/₁₀₀

= ^{12000 × 10}/₁₀₀

= ¹²⁰⁰⁰⁰/₁₀₀

= $1200

Thus, Simple Interest = $1200

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 = $6000 + $1200

= $7200

Thus, Amount to be paid = $7200 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 = $6000

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

And, Time (t) = 10 years

Thus, Amount (A)

= $6000 + ($6000 × 2% × 10)

= $6000 + ($6000 ײ/₁₀₀ × 10)

= $6000 + (^{6000 × 2 × 10}/₁₀₀)

= $6000 + (^{12000 × 10}/₁₀₀)

= $6000 + (¹²⁰⁰⁰⁰/₁₀₀)

= $6000 + $1200 = $7200

Thus, Amount (A) to be paid = $7200 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 $6000, the simple interest in 1 year

= ²/₁₀₀ × 6000

= ^{2 × 6000}/₁₀₀

= ¹²⁰⁰⁰/₁₀₀ = $120

Thus, simple interest for 1 year = $120

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $120 × 10 = $1200

Thus, Simple Interest (SI) = $1200

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $1200

= $7200

Thus, Amount to be paid = $7200 Answer

Similar Questions

(1) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 9% simple interest?

(2) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $8965 to clear the loan, then find the time period of the loan.

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

(4) If Elizabeth paid $4002 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(5) If Patricia borrowed $3150 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(6) Betty took a loan of $6500 at the rate of 7% simple interest per annum. If he paid an amount of $10140 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 5% simple interest.

(8) What amount does Christopher have to pay after 5 years if he takes a loan of $4000 at 2% simple interest?

(9) Karen took a loan of $5900 at the rate of 7% simple interest per annum. If he paid an amount of $10030 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 3% simple interest for 4 years.