Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 6% simple interest.

Correct Answer  $9520

Solution & Explanation

Solution

Given,

Principal (P) = $5950

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) = $5950 × 6% × 10

= $5950 ×⁶/₁₀₀ × 10

= ^{5950 × 6 × 10}/₁₀₀

= ^{35700 × 10}/₁₀₀

= ³⁵⁷⁰⁰⁰/₁₀₀

= $3570

Thus, Simple Interest = $3570

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 = $5950 + $3570

= $9520

Thus, Amount to be paid = $9520 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 = $5950

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5950 + ($5950 × 6% × 10)

= $5950 + ($5950 ×⁶/₁₀₀ × 10)

= $5950 + (^{5950 × 6 × 10}/₁₀₀)

= $5950 + (^{35700 × 10}/₁₀₀)

= $5950 + (³⁵⁷⁰⁰⁰/₁₀₀)

= $5950 + $3570 = $9520

Thus, Amount (A) to be paid = $9520 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 $5950, the simple interest in 1 year

= ⁶/₁₀₀ × 5950

= ^{6 × 5950}/₁₀₀

= ³⁵⁷⁰⁰/₁₀₀ = $357

Thus, simple interest for 1 year = $357

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $357 × 10 = $3570

Thus, Simple Interest (SI) = $3570

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $3570

= $9520

Thus, Amount to be paid = $9520 Answer

Similar Questions

(1) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $8326 to clear the loan, then find the time period of the loan.

(2) Christopher took a loan of $6000 at the rate of 6% simple interest per annum. If he paid an amount of $9240 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if Michael borrowed a sum of $3300 at 4% simple interest for 3 years.

(4) Calculate the amount due if Patricia borrowed a sum of $3150 at 9% simple interest for 3 years.

(5) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 2% simple interest?

(6) Find the amount to be paid if Patricia borrowed a sum of $5150 at 3% simple interest for 8 years.

(7) In how much time a principal of $3200 will amount to $3520 at a simple interest of 2% per annum?

(8) Calculate the amount due if Linda borrowed a sum of $3350 at 10% simple interest for 4 years.

(9) Find the amount to be paid if Richard borrowed a sum of $5600 at 10% simple interest for 7 years.

(10) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 9% simple interest.