Simple Interest
Math MCQs

Question :    Calculate the amount due if Jennifer borrowed a sum of $3250 at 6% simple interest for 3 years.

Correct Answer  $3835

Solution & Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 6%

Time (t) = 3 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) = $3250 × 6% × 3

= $3250 ×⁶/₁₀₀ × 3

= ^{3250 × 6 × 3}/₁₀₀

= ^{19500 × 3}/₁₀₀

= ⁵⁸⁵⁰⁰/₁₀₀

= $585

Thus, Simple Interest = $585

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 = $3250 + $585

= $3835

Thus, Amount to be paid = $3835 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 = $3250

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

And, Time (t) = 3 years

Thus, Amount (A)

= $3250 + ($3250 × 6% × 3)

= $3250 + ($3250 ×⁶/₁₀₀ × 3)

= $3250 + (^{3250 × 6 × 3}/₁₀₀)

= $3250 + (^{19500 × 3}/₁₀₀)

= $3250 + (⁵⁸⁵⁰⁰/₁₀₀)

= $3250 + $585 = $3835

Thus, Amount (A) to be paid = $3835 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 $3250, the simple interest in 1 year

= ⁶/₁₀₀ × 3250

= ^{6 × 3250}/₁₀₀

= ¹⁹⁵⁰⁰/₁₀₀ = $195

Thus, simple interest for 1 year = $195

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $195 × 3 = $585

Thus, Simple Interest (SI) = $585

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $585

= $3835

Thus, Amount to be paid = $3835 Answer

Similar Questions

(1) Mary had to pay $3416 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(2) Find the amount to be paid if Sarah borrowed a sum of $5850 at 7% simple interest for 8 years.

(3) Kenneth had to pay $5750 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(4) How much loan did Timothy borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8880 to clear it?

(5) Daniel took a loan of $6200 at the rate of 6% simple interest per annum. If he paid an amount of $9548 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 10% simple interest.

(7) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 3% simple interest.

(8) Find the amount to be paid if David borrowed a sum of $5400 at 2% simple interest for 8 years.

(9) What amount does John have to pay after 5 years if he takes a loan of $3200 at 6% simple interest?

(10) If Jessica borrowed $3750 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.