Simple Interest
Math MCQs

Question :    What amount does Michael have to pay after 5 years if he takes a loan of $3300 at 6% simple interest?

Correct Answer  $4290

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3300 × 6% × 5

= $3300 ×⁶/₁₀₀ × 5

= ^{3300 × 6 × 5}/₁₀₀

= ^{19800 × 5}/₁₀₀

= ⁹⁹⁰⁰⁰/₁₀₀

= $990

Thus, Simple Interest = $990

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 = $3300 + $990

= $4290

Thus, Amount to be paid = $4290 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 = $3300

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3300 + ($3300 × 6% × 5)

= $3300 + ($3300 ×⁶/₁₀₀ × 5)

= $3300 + (^{3300 × 6 × 5}/₁₀₀)

= $3300 + (^{19800 × 5}/₁₀₀)

= $3300 + (⁹⁹⁰⁰⁰/₁₀₀)

= $3300 + $990 = $4290

Thus, Amount (A) to be paid = $4290 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $3300, the simple interest in 1 year

= ⁶/₁₀₀ × 3300

= ^{6 × 3300}/₁₀₀

= ¹⁹⁸⁰⁰/₁₀₀ = $198

Thus, simple interest for 1 year = $198

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $198 × 5 = $990

Thus, Simple Interest (SI) = $990

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $990

= $4290

Thus, Amount to be paid = $4290 Answer

Similar Questions

(1) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $10620 to clear the loan, then find the time period of the loan.

(2) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 9% simple interest?

(3) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.

(4) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 3% simple interest?

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

(6) Donald took a loan of $7000 at the rate of 8% simple interest per annum. If he paid an amount of $10360 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due if Jessica borrowed a sum of $3750 at 9% simple interest for 4 years.

(8) Joseph had to pay $4033 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $8428 to clear the loan, then find the time period of the loan.

(10) In how much time a principal of $3150 will amount to $3433.5 at a simple interest of 3% per annum?