Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if John borrowed a sum of $3100 at a 6% simple interest?

Correct Answer  $3472

Solution & Explanation

Solution

Given,

Principal (P) = $3100

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) = $3100 × 6% × 2

= $3100 ×⁶/₁₀₀ × 2

= ^{3100 × 6 × 2}/₁₀₀

= ^{18600 × 2}/₁₀₀

= ³⁷²⁰⁰/₁₀₀

= $372

Thus, Simple Interest = $372

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 = $3100 + $372

= $3472

Thus, Amount to be paid = $3472 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 = $3100

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3100 + ($3100 × 6% × 2)

= $3100 + ($3100 ×⁶/₁₀₀ × 2)

= $3100 + (^{3100 × 6 × 2}/₁₀₀)

= $3100 + (^{18600 × 2}/₁₀₀)

= $3100 + (³⁷²⁰⁰/₁₀₀)

= $3100 + $372 = $3472

Thus, Amount (A) to be paid = $3472 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 $3100, the simple interest in 1 year

= ⁶/₁₀₀ × 3100

= ^{6 × 3100}/₁₀₀

= ¹⁸⁶⁰⁰/₁₀₀ = $186

Thus, simple interest for 1 year = $186

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $186 × 2 = $372

Thus, Simple Interest (SI) = $372

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3100 + $372

= $3472

Thus, Amount to be paid = $3472 Answer

Similar Questions

(1) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 2% simple interest?

(2) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $7396 to clear the loan, then find the time period of the loan.

(3) Nancy took a loan of $6300 at the rate of 9% simple interest per annum. If he paid an amount of $9702 to clear the loan, then find the time period of the loan.

(4) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $10332 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Joseph borrowed a sum of $3700 at 4% simple interest for 3 years.

(6) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 5% simple interest?

(7) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $10200 to clear the loan, then find the time period of the loan.

(8) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $13600 to clear the loan, then find the time period of the loan.

(9) If Paul paid $5640 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(10) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 4% simple interest?