Simple Interest
Math MCQs

Question :  ( 1 of 10 )  Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 5% simple interest.

Correct Answer  $7875

Solution & Explanation

Solution

Given,

Principal (P) = $5250

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) = $5250 × 5% × 10

= $5250 ×⁵/₁₀₀ × 10

= ^{5250 × 5 × 10}/₁₀₀

= ^{26250 × 10}/₁₀₀

= ²⁶²⁵⁰⁰/₁₀₀

= $2625

Thus, Simple Interest = $2625

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 + $2625

= $7875

Thus, Amount to be paid = $7875 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) = 5%

And, Time (t) = 10 years

Thus, Amount (A)

= $5250 + ($5250 × 5% × 10)

= $5250 + ($5250 ×⁵/₁₀₀ × 10)

= $5250 + (^{5250 × 5 × 10}/₁₀₀)

= $5250 + (^{26250 × 10}/₁₀₀)

= $5250 + (²⁶²⁵⁰⁰/₁₀₀)

= $5250 + $2625 = $7875

Thus, Amount (A) to be paid = $7875 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 $5250, the simple interest in 1 year

= ⁵/₁₀₀ × 5250

= ^{5 × 5250}/₁₀₀

= ²⁶²⁵⁰/₁₀₀ = $262.5

Thus, simple interest for 1 year = $262.5

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $262.5 × 10 = $2625

Thus, Simple Interest (SI) = $2625

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $2625

= $7875

Thus, Amount to be paid = $7875 Answer

Similar Questions

(1) Matthew took a loan of $6400 at the rate of 10% simple interest per annum. If he paid an amount of $12160 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 8% simple interest.

(3) What amount does William have to pay after 5 years if he takes a loan of $3500 at 7% simple interest?

(4) Margaret had to pay $5002.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(5) Jessica had to pay $4312.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(6) Paul had to pay $5123 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(7) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 7 years.

(8) In how much time a principal of $3000 will amount to $3600 at a simple interest of 4% per annum?

(9) Calculate the amount due if Susan borrowed a sum of $3650 at 7% simple interest for 4 years.

(10) Betty had to pay $4760 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.