Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 3% simple interest.

Correct Answer  $7556.5

Solution & Explanation

Solution

Given,

Principal (P) = $5950

Rate of Simple Interest (SI) = 3%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5950 × 3% × 9

= $5950 ׳/₁₀₀ × 9

= ^{5950 × 3 × 9}/₁₀₀

= ^{17850 × 9}/₁₀₀

= ¹⁶⁰⁶⁵⁰/₁₀₀

= $1606.5

Thus, Simple Interest = $1606.5

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 = $5950 + $1606.5

= $7556.5

Thus, Amount to be paid = $7556.5 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 = $5950

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 9 years

Thus, Amount (A)

= $5950 + ($5950 × 3% × 9)

= $5950 + ($5950 ׳/₁₀₀ × 9)

= $5950 + (^{5950 × 3 × 9}/₁₀₀)

= $5950 + (^{17850 × 9}/₁₀₀)

= $5950 + (¹⁶⁰⁶⁵⁰/₁₀₀)

= $5950 + $1606.5 = $7556.5

Thus, Amount (A) to be paid = $7556.5 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5950, the simple interest in 1 year

= ³/₁₀₀ × 5950

= ^{3 × 5950}/₁₀₀

= ¹⁷⁸⁵⁰/₁₀₀ = $178.5

Thus, simple interest for 1 year = $178.5

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $178.5 × 9 = $1606.5

Thus, Simple Interest (SI) = $1606.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $1606.5

= $7556.5

Thus, Amount to be paid = $7556.5 Answer

Similar Questions

(1) Find the amount to be paid if Sarah borrowed a sum of $5850 at 8% simple interest for 8 years.

(2) Find the amount to be paid if Susan borrowed a sum of $5650 at 10% simple interest for 7 years.

(3) Find the amount to be paid if William borrowed a sum of $5500 at 6% simple interest for 7 years.

(4) Find the amount to be paid if Michael borrowed a sum of $5300 at 2% simple interest for 7 years.

(5) How much loan did Ashley borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7860 to clear it?

(6) Elizabeth took a loan of $4900 at the rate of 10% simple interest per annum. If he paid an amount of $9310 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due if Susan borrowed a sum of $3650 at 10% simple interest for 3 years.

(8) If Daniel paid $4592 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) How much loan did Steven borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8250 to clear it?

(10) Find the amount to be paid if Thomas borrowed a sum of $5800 at 7% simple interest for 8 years.