Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 6% simple interest.

Correct Answer  $8560

Solution & Explanation

Solution

Given,

Principal (P) = $5350

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) = $5350 × 6% × 10

= $5350 ×⁶/₁₀₀ × 10

= ^{5350 × 6 × 10}/₁₀₀

= ^{32100 × 10}/₁₀₀

= ³²¹⁰⁰⁰/₁₀₀

= $3210

Thus, Simple Interest = $3210

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 = $5350 + $3210

= $8560

Thus, Amount to be paid = $8560 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 = $5350

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5350 + ($5350 × 6% × 10)

= $5350 + ($5350 ×⁶/₁₀₀ × 10)

= $5350 + (^{5350 × 6 × 10}/₁₀₀)

= $5350 + (^{32100 × 10}/₁₀₀)

= $5350 + (³²¹⁰⁰⁰/₁₀₀)

= $5350 + $3210 = $8560

Thus, Amount (A) to be paid = $8560 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 $5350, the simple interest in 1 year

= ⁶/₁₀₀ × 5350

= ^{6 × 5350}/₁₀₀

= ³²¹⁰⁰/₁₀₀ = $321

Thus, simple interest for 1 year = $321

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $321 × 10 = $3210

Thus, Simple Interest (SI) = $3210

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $3210

= $8560

Thus, Amount to be paid = $8560 Answer

Similar Questions

(1) Calculate the amount due if Karen borrowed a sum of $3950 at 9% simple interest for 3 years.

(2) Calculate the amount due if Joseph borrowed a sum of $3700 at 6% simple interest for 3 years.

(3) Calculate the amount due if Joseph borrowed a sum of $3700 at 8% simple interest for 4 years.

(4) John took a loan of $4400 at the rate of 10% simple interest per annum. If he paid an amount of $8360 to clear the loan, then find the time period of the loan.

(5) If Jennifer paid $3770 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(6) Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 3% simple interest.

(7) What amount does John have to pay after 6 years if he takes a loan of $3200 at 10% simple interest?

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

(9) If Donna paid $5626 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $8428 to clear the loan, then find the time period of the loan.