Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if William borrowed a sum of $3250 at a 10% simple interest?

Correct Answer  $3900

Solution & Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 10%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3250 × 10% × 2

= $3250 ×¹⁰/₁₀₀ × 2

= ^{3250 × 10 × 2}/₁₀₀

= ^{32500 × 2}/₁₀₀

= ⁶⁵⁰⁰⁰/₁₀₀

= $650

Thus, Simple Interest = $650

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 = $3250 + $650

= $3900

Thus, Amount to be paid = $3900 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 = $3250

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 2 years

Thus, Amount (A)

= $3250 + ($3250 × 10% × 2)

= $3250 + ($3250 ×¹⁰/₁₀₀ × 2)

= $3250 + (^{3250 × 10 × 2}/₁₀₀)

= $3250 + (^{32500 × 2}/₁₀₀)

= $3250 + (⁶⁵⁰⁰⁰/₁₀₀)

= $3250 + $650 = $3900

Thus, Amount (A) to be paid = $3900 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = ¹⁰/₁₀₀

∴ For $3250, the simple interest in 1 year

= ¹⁰/₁₀₀ × 3250

= ^{10 × 3250}/₁₀₀

= ³²⁵⁰⁰/₁₀₀ = $325

Thus, simple interest for 1 year = $325

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $325 × 2 = $650

Thus, Simple Interest (SI) = $650

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $650

= $3900

Thus, Amount to be paid = $3900 Answer

Similar Questions

(1) Susan took a loan of $5300 at the rate of 7% simple interest per annum. If he paid an amount of $7897 to clear the loan, then find the time period of the loan.

(2) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 9% simple interest?

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

(4) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 8% simple interest?

(5) Find the amount to be paid if Robert borrowed a sum of $5100 at 9% simple interest for 7 years.

(6) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11222 to clear the loan, then find the time period of the loan.

(7) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 6% simple interest?

(8) Calculate the amount due if Thomas borrowed a sum of $3800 at 9% simple interest for 4 years.

(9) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $9180 to clear the loan, then find the time period of the loan.

(10) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $8313 to clear the loan, then find the time period of the loan.