Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Michael borrowed a sum of $5300 at a rate of 5% simple interest.

Correct Answer  $7950

Solution & Explanation

Solution

Given,

Principal (P) = $5300

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) = $5300 × 5% × 10

= $5300 ×⁵/₁₀₀ × 10

= ^{5300 × 5 × 10}/₁₀₀

= ^{26500 × 10}/₁₀₀

= ²⁶⁵⁰⁰⁰/₁₀₀

= $2650

Thus, Simple Interest = $2650

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 = $5300 + $2650

= $7950

Thus, Amount to be paid = $7950 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 = $5300

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 10 years

Thus, Amount (A)

= $5300 + ($5300 × 5% × 10)

= $5300 + ($5300 ×⁵/₁₀₀ × 10)

= $5300 + (^{5300 × 5 × 10}/₁₀₀)

= $5300 + (^{26500 × 10}/₁₀₀)

= $5300 + (²⁶⁵⁰⁰⁰/₁₀₀)

= $5300 + $2650 = $7950

Thus, Amount (A) to be paid = $7950 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 $5300, the simple interest in 1 year

= ⁵/₁₀₀ × 5300

= ^{5 × 5300}/₁₀₀

= ²⁶⁵⁰⁰/₁₀₀ = $265

Thus, simple interest for 1 year = $265

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $265 × 10 = $2650

Thus, Simple Interest (SI) = $2650

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5300 + $2650

= $7950

Thus, Amount to be paid = $7950 Answer

Similar Questions

(1) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $9702 to clear the loan, then find the time period of the loan.

(2) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $10320 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 9% simple interest.

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 8% simple interest?

(5) Find the amount to be paid if Joseph borrowed a sum of $5700 at 5% simple interest for 8 years.

(6) Find the amount to be paid if Sarah borrowed a sum of $5850 at 7% simple interest for 8 years.

(7) Calculate the amount due if Barbara borrowed a sum of $3550 at 3% simple interest for 3 years.

(8) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 8% simple interest?

(9) Lisa had to pay $4536 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(10) What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 6% simple interest?