Simple Interest
Math MCQs

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

Correct Answer  $4488

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 6%

Time (t) = 6 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% × 6

= $3300 ×⁶/₁₀₀ × 6

= ^{3300 × 6 × 6}/₁₀₀

= ^{19800 × 6}/₁₀₀

= ¹¹⁸⁸⁰⁰/₁₀₀

= $1188

Thus, Simple Interest = $1188

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 + $1188

= $4488

Thus, Amount to be paid = $4488 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) = 6 years

Thus, Amount (A)

= $3300 + ($3300 × 6% × 6)

= $3300 + ($3300 ×⁶/₁₀₀ × 6)

= $3300 + (^{3300 × 6 × 6}/₁₀₀)

= $3300 + (^{19800 × 6}/₁₀₀)

= $3300 + (¹¹⁸⁸⁰⁰/₁₀₀)

= $3300 + $1188 = $4488

Thus, Amount (A) to be paid = $4488 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 6 years

= Simple interest for 1 year × 6

= $198 × 6 = $1188

Thus, Simple Interest (SI) = $1188

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $1188

= $4488

Thus, Amount to be paid = $4488 Answer

Similar Questions

(1) Thomas took a loan of $5600 at the rate of 8% simple interest per annum. If he paid an amount of $8736 to clear the loan, then find the time period of the loan.

(2) How much loan did Edward borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9120 to clear it?

(3) If Lisa paid $4374 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(4) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.

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

(7) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 2% simple interest?

(8) Michael took a loan of $4600 at the rate of 10% simple interest per annum. If he paid an amount of $9200 to clear the loan, then find the time period of the loan.

(9) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 3% simple interest?

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