Simple Interest
Math MCQs

Question :    Find the amount to be paid if Jennifer borrowed a sum of $5250 at 10% simple interest for 7 years.

Correct Answer  $8925

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 10%

Time (t) = 7 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) = $5250 × 10% × 7

= $5250 ×¹⁰/₁₀₀ × 7

= ^{5250 × 10 × 7}/₁₀₀

= ^{52500 × 7}/₁₀₀

= ³⁶⁷⁵⁰⁰/₁₀₀

= $3675

Thus, Simple Interest = $3675

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 = $5250 + $3675

= $8925

Thus, Amount to be paid = $8925 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 = $5250

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

And, Time (t) = 7 years

Thus, Amount (A)

= $5250 + ($5250 × 10% × 7)

= $5250 + ($5250 ×¹⁰/₁₀₀ × 7)

= $5250 + (^{5250 × 10 × 7}/₁₀₀)

= $5250 + (^{52500 × 7}/₁₀₀)

= $5250 + (³⁶⁷⁵⁰⁰/₁₀₀)

= $5250 + $3675 = $8925

Thus, Amount (A) to be paid = $8925 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 $5250, the simple interest in 1 year

= ¹⁰/₁₀₀ × 5250

= ^{10 × 5250}/₁₀₀

= ⁵²⁵⁰⁰/₁₀₀ = $525

Thus, simple interest for 1 year = $525

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $525 × 7 = $3675

Thus, Simple Interest (SI) = $3675

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3675

= $8925

Thus, Amount to be paid = $8925 Answer

Similar Questions

(1) Find the amount to be paid if Linda borrowed a sum of $5350 at 6% simple interest for 7 years.

(2) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 8% simple interest.

(3) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 10% simple interest.

(4) Patricia took a loan of $4300 at the rate of 6% simple interest per annum. If he paid an amount of $6622 to clear the loan, then find the time period of the loan.

(5) How much loan did David borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6210 to clear it?

(6) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $9324 to clear the loan, then find the time period of the loan.

(7) Find the amount to be paid if John borrowed a sum of $5200 at 7% simple interest for 7 years.

(8) If David borrowed $3400 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(9) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $11152 to clear the loan, then find the time period of the loan.

(10) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $10608 to clear the loan, then find the time period of the loan.