Simple Interest
Math MCQs

Question :    What amount does John have to pay after 6 years if he takes a loan of $3200 at 2% simple interest?

Correct Answer  $3584

Solution & Explanation

Solution

Given,

Principal (P) = $3200

Rate of Simple Interest (SI) = 2%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $3200 × 2% × 6

= $3200 ײ/₁₀₀ × 6

= ^{3200 × 2 × 6}/₁₀₀

= ^{6400 × 6}/₁₀₀

= ³⁸⁴⁰⁰/₁₀₀

= $384

Thus, Simple Interest = $384

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 = $3200 + $384

= $3584

Thus, Amount to be paid = $3584 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 = $3200

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 6 years

Thus, Amount (A)

= $3200 + ($3200 × 2% × 6)

= $3200 + ($3200 ײ/₁₀₀ × 6)

= $3200 + (^{3200 × 2 × 6}/₁₀₀)

= $3200 + (^{6400 × 6}/₁₀₀)

= $3200 + (³⁸⁴⁰⁰/₁₀₀)

= $3200 + $384 = $3584

Thus, Amount (A) to be paid = $3584 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $3200, the simple interest in 1 year

= ²/₁₀₀ × 3200

= ^{2 × 3200}/₁₀₀

= ⁶⁴⁰⁰/₁₀₀ = $64

Thus, simple interest for 1 year = $64

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $64 × 6 = $384

Thus, Simple Interest (SI) = $384

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3200 + $384

= $3584

Thus, Amount to be paid = $3584 Answer

Similar Questions

(1) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $10640 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 6% simple interest?

(3) If Kimberly paid $5580 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(4) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 2% simple interest.

(5) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 10% simple interest.

(6) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 9% simple interest.

(7) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 8 years.

(8) What amount does Elizabeth have to pay after 5 years if he takes a loan of $3450 at 5% simple interest?

(9) How much loan did Elizabeth borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6540 to clear it?

(10) Joseph took a loan of $5400 at the rate of 9% simple interest per annum. If he paid an amount of $8316 to clear the loan, then find the time period of the loan.