Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 4% simple interest.

Correct Answer  $7276

Solution & Explanation

Solution

Given,

Principal (P) = $5350

Rate of Simple Interest (SI) = 4%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $5350 × 4% × 9

= $5350 ×⁴/₁₀₀ × 9

= ^{5350 × 4 × 9}/₁₀₀

= ^{21400 × 9}/₁₀₀

= ¹⁹²⁶⁰⁰/₁₀₀

= $1926

Thus, Simple Interest = $1926

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 = $5350 + $1926

= $7276

Thus, Amount to be paid = $7276 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 = $5350

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 9 years

Thus, Amount (A)

= $5350 + ($5350 × 4% × 9)

= $5350 + ($5350 ×⁴/₁₀₀ × 9)

= $5350 + (^{5350 × 4 × 9}/₁₀₀)

= $5350 + (^{21400 × 9}/₁₀₀)

= $5350 + (¹⁹²⁶⁰⁰/₁₀₀)

= $5350 + $1926 = $7276

Thus, Amount (A) to be paid = $7276 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = ⁴/₁₀₀

∴ For $5350, the simple interest in 1 year

= ⁴/₁₀₀ × 5350

= ^{4 × 5350}/₁₀₀

= ²¹⁴⁰⁰/₁₀₀ = $214

Thus, simple interest for 1 year = $214

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $214 × 9 = $1926

Thus, Simple Interest (SI) = $1926

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $1926

= $7276

Thus, Amount to be paid = $7276 Answer

Similar Questions

(1) Linda took a loan of $4700 at the rate of 6% simple interest per annum. If he paid an amount of $6956 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 4% simple interest.

(3) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $8736 to clear the loan, then find the time period of the loan.

(4) What amount does Michael have to pay after 5 years if he takes a loan of $3300 at 2% simple interest?

(5) Karen had to pay $4305.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(6) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 5% simple interest.

(7) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 10% simple interest?

(8) How much loan did Brian borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7920 to clear it?

(9) In how much time a principal of $3200 will amount to $3584 at a simple interest of 3% per annum?

(10) Calculate the amount due if Patricia borrowed a sum of $3150 at 5% simple interest for 3 years.