Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 6% simple interest.

Correct Answer  $8320

Solution & Explanation

Solution

Given,

Principal (P) = $5200

Rate of Simple Interest (SI) = 6%

Time (t) = 10 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) = $5200 × 6% × 10

= $5200 ×⁶/₁₀₀ × 10

= ^{5200 × 6 × 10}/₁₀₀

= ^{31200 × 10}/₁₀₀

= ³¹²⁰⁰⁰/₁₀₀

= $3120

Thus, Simple Interest = $3120

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 = $5200 + $3120

= $8320

Thus, Amount to be paid = $8320 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 = $5200

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5200 + ($5200 × 6% × 10)

= $5200 + ($5200 ×⁶/₁₀₀ × 10)

= $5200 + (^{5200 × 6 × 10}/₁₀₀)

= $5200 + (^{31200 × 10}/₁₀₀)

= $5200 + (³¹²⁰⁰⁰/₁₀₀)

= $5200 + $3120 = $8320

Thus, Amount (A) to be paid = $8320 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 $5200, the simple interest in 1 year

= ⁶/₁₀₀ × 5200

= ^{6 × 5200}/₁₀₀

= ³¹²⁰⁰/₁₀₀ = $312

Thus, simple interest for 1 year = $312

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $312 × 10 = $3120

Thus, Simple Interest (SI) = $3120

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5200 + $3120

= $8320

Thus, Amount to be paid = $8320 Answer

Similar Questions

(1) Sarah took a loan of $5700 at the rate of 7% simple interest per annum. If he paid an amount of $9291 to clear the loan, then find the time period of the loan.

(2) If Karen paid $4424 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(3) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $9672 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 2% simple interest for 7 years.

(5) Find the amount to be paid if Susan borrowed a sum of $5650 at 10% simple interest for 7 years.

(6) If Joshua paid $5488 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(7) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $10836 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3150 will amount to $3528 at a simple interest of 3% per annum?

(9) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 7% simple interest.

(10) Calculate the amount due if Susan borrowed a sum of $3650 at 2% simple interest for 4 years.