Simple Interest
Math MCQs

Question :    Calculate the amount due if Linda borrowed a sum of $3350 at 7% simple interest for 3 years.

Correct Answer  $4053.5

Solution & Explanation

Solution

Given,

Principal (P) = $3350

Rate of Simple Interest (SI) = 7%

Time (t) = 3 years

Thus, Amount (A) = ?

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

Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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) = $3350 × 7% × 3

= $3350 ×⁷/₁₀₀ × 3

= ^{3350 × 7 × 3}/₁₀₀

= ^{23450 × 3}/₁₀₀

= ⁷⁰³⁵⁰/₁₀₀

= $703.5

Thus, Simple Interest = $703.5

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 = $3350 + $703.5

= $4053.5

Thus, Amount to be paid = $4053.5 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 = $3350

Rate of Simple Interest (SI) or (R) = 7%

And, Time (t) = 3 years

Thus, Amount (A)

= $3350 + ($3350 × 7% × 3)

= $3350 + ($3350 ×⁷/₁₀₀ × 3)

= $3350 + (^{3350 × 7 × 3}/₁₀₀)

= $3350 + (^{23450 × 3}/₁₀₀)

= $3350 + (⁷⁰³⁵⁰/₁₀₀)

= $3350 + $703.5 = $4053.5

Thus, Amount (A) to be paid = $4053.5 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 7%

This, means, $7 per $100 per year

∵ For $100, the simple interest for 1 year = $7

∴ For $1, the simple interest for 1 year = ⁷/₁₀₀

∴ For $3350, the simple interest in 1 year

= ⁷/₁₀₀ × 3350

= ^{7 × 3350}/₁₀₀

= ²³⁴⁵⁰/₁₀₀ = $234.5

Thus, simple interest for 1 year = $234.5

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $234.5 × 3 = $703.5

Thus, Simple Interest (SI) = $703.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3350 + $703.5

= $4053.5

Thus, Amount to be paid = $4053.5 Answer

Similar Questions

(1) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 8% simple interest.

(2) In how much time a principal of $3050 will amount to $3355 at a simple interest of 2% per annum?

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

(4) David took a loan of $4800 at the rate of 8% simple interest per annum. If he paid an amount of $7488 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Susan borrowed a sum of $3650 at 7% simple interest for 4 years.

(6) Find the amount to be paid if Patricia borrowed a sum of $5150 at 2% simple interest for 7 years.

(7) Find the amount to be paid if William borrowed a sum of $5500 at 3% simple interest for 8 years.

(8) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 7% simple interest.

(9) Calculate the amount due if Barbara borrowed a sum of $3550 at 2% simple interest for 3 years.

(10) What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 6% simple interest?