Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 6% simple interest?

Correct Answer  $3696

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 6%

Time (t) = 2 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% × 2

= $3300 ×⁶/₁₀₀ × 2

= ^{3300 × 6 × 2}/₁₀₀

= ^{19800 × 2}/₁₀₀

= ³⁹⁶⁰⁰/₁₀₀

= $396

Thus, Simple Interest = $396

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 + $396

= $3696

Thus, Amount to be paid = $3696 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) = 2 years

Thus, Amount (A)

= $3300 + ($3300 × 6% × 2)

= $3300 + ($3300 ×⁶/₁₀₀ × 2)

= $3300 + (^{3300 × 6 × 2}/₁₀₀)

= $3300 + (^{19800 × 2}/₁₀₀)

= $3300 + (³⁹⁶⁰⁰/₁₀₀)

= $3300 + $396 = $3696

Thus, Amount (A) to be paid = $3696 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 2 years

= Simple interest for 1 year × 2

= $198 × 2 = $396

Thus, Simple Interest (SI) = $396

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $396

= $3696

Thus, Amount to be paid = $3696 Answer

Similar Questions

(1) What amount does James have to pay after 6 years if he takes a loan of $3000 at 3% simple interest?

(2) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 8% simple interest?

(3) Find the amount to be paid if James borrowed a sum of $5000 at 4% simple interest for 8 years.

(4) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 3% simple interest?

(5) Find the amount to be paid if Charles borrowed a sum of $5900 at 10% simple interest for 8 years.

(6) Betty took a loan of $6500 at the rate of 7% simple interest per annum. If he paid an amount of $11050 to clear the loan, then find the time period of the loan.

(7) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 10% simple interest?

(8) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 5% simple interest?

(9) In how much time a principal of $3200 will amount to $3392 at a simple interest of 3% per annum?

(10) How much loan did Donald borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7475 to clear it?