Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 4% simple interest?

Correct Answer  $3564

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 4%

Time (t) = 2 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) = $3300 × 4% × 2

= $3300 ×⁴/₁₀₀ × 2

= ^{3300 × 4 × 2}/₁₀₀

= ^{13200 × 2}/₁₀₀

= ²⁶⁴⁰⁰/₁₀₀

= $264

Thus, Simple Interest = $264

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 + $264

= $3564

Thus, Amount to be paid = $3564 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) = 4%

And, Time (t) = 2 years

Thus, Amount (A)

= $3300 + ($3300 × 4% × 2)

= $3300 + ($3300 ×⁴/₁₀₀ × 2)

= $3300 + (^{3300 × 4 × 2}/₁₀₀)

= $3300 + (^{13200 × 2}/₁₀₀)

= $3300 + (²⁶⁴⁰⁰/₁₀₀)

= $3300 + $264 = $3564

Thus, Amount (A) to be paid = $3564 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 $3300, the simple interest in 1 year

= ⁴/₁₀₀ × 3300

= ^{4 × 3300}/₁₀₀

= ¹³²⁰⁰/₁₀₀ = $132

Thus, simple interest for 1 year = $132

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $132 × 2 = $264

Thus, Simple Interest (SI) = $264

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $264

= $3564

Thus, Amount to be paid = $3564 Answer

Similar Questions

(1) Find the amount to be paid if Joseph borrowed a sum of $5700 at 2% simple interest for 7 years.

(2) Find the amount to be paid if Richard borrowed a sum of $5600 at 6% simple interest for 8 years.

(3) Jennifer took a loan of $4500 at the rate of 10% simple interest per annum. If he paid an amount of $9000 to clear the loan, then find the time period of the loan.

(4) Elizabeth had to pay $3657 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) Find the amount to be paid if Mary borrowed a sum of $5050 at 9% simple interest for 8 years.

(6) How much loan did Carol borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8107.5 to clear it?

(7) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $11008 to clear the loan, then find the time period of the loan.

(8) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 6% simple interest?

(9) What amount will be due after 2 years if John borrowed a sum of $3100 at a 10% simple interest?

(10) Jennifer took a loan of $4500 at the rate of 10% simple interest per annum. If he paid an amount of $7200 to clear the loan, then find the time period of the loan.