Simple Interest
Math MCQs

Question :    What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 10% simple interest?

Correct Answer  $4875

Solution & Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 10%

Time (t) = 5 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% × 5

= $3250 ×¹⁰/₁₀₀ × 5

= ^{3250 × 10 × 5}/₁₀₀

= ^{32500 × 5}/₁₀₀

= ¹⁶²⁵⁰⁰/₁₀₀

= $1625

Thus, Simple Interest = $1625

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 + $1625

= $4875

Thus, Amount to be paid = $4875 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) = 5 years

Thus, Amount (A)

= $3250 + ($3250 × 10% × 5)

= $3250 + ($3250 ×¹⁰/₁₀₀ × 5)

= $3250 + (^{3250 × 10 × 5}/₁₀₀)

= $3250 + (^{32500 × 5}/₁₀₀)

= $3250 + (¹⁶²⁵⁰⁰/₁₀₀)

= $3250 + $1625 = $4875

Thus, Amount (A) to be paid = $4875 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 5 years

= Simple interest for 1 year × 5

= $325 × 5 = $1625

Thus, Simple Interest (SI) = $1625

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $1625

= $4875

Thus, Amount to be paid = $4875 Answer

Similar Questions

(1) Calculate the amount due if Susan borrowed a sum of $3650 at 9% simple interest for 4 years.

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

(3) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $6532 to clear the loan, then find the time period of the loan.

(4) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 10% simple interest?

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

(6) In how much time a principal of $3100 will amount to $3472 at a simple interest of 4% per annum?

(7) Calculate the amount due if Karen borrowed a sum of $3950 at 7% simple interest for 3 years.

(8) Calculate the amount due if Sarah borrowed a sum of $3850 at 9% simple interest for 3 years.

(9) In how much time a principal of $3150 will amount to $3654 at a simple interest of 4% per annum?

(10) Find the amount to be paid if Mary borrowed a sum of $5050 at 5% simple interest for 8 years.