Simple Interest
Math MCQs

Question :    Find the amount to be paid if Jennifer borrowed a sum of $5250 at 9% simple interest for 8 years.

Correct Answer  $9030

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 9%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5250 × 9% × 8

= $5250 ×⁹/₁₀₀ × 8

= ^{5250 × 9 × 8}/₁₀₀

= ^{47250 × 8}/₁₀₀

= ³⁷⁸⁰⁰⁰/₁₀₀

= $3780

Thus, Simple Interest = $3780

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 = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 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 = $5250

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 8 years

Thus, Amount (A)

= $5250 + ($5250 × 9% × 8)

= $5250 + ($5250 ×⁹/₁₀₀ × 8)

= $5250 + (^{5250 × 9 × 8}/₁₀₀)

= $5250 + (^{47250 × 8}/₁₀₀)

= $5250 + (³⁷⁸⁰⁰⁰/₁₀₀)

= $5250 + $3780 = $9030

Thus, Amount (A) to be paid = $9030 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁹/₁₀₀ × 5250

= ^{9 × 5250}/₁₀₀

= ⁴⁷²⁵⁰/₁₀₀ = $472.5

Thus, simple interest for 1 year = $472.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $472.5 × 8 = $3780

Thus, Simple Interest (SI) = $3780

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 Answer

Similar Questions

(1) In how much time a principal of $3100 will amount to $3875 at a simple interest of 5% per annum?

(2) If Patricia borrowed $3150 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(3) How much loan did Edward borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8740 to clear it?

(4) What amount does James have to pay after 5 years if he takes a loan of $3000 at 3% simple interest?

(5) Find the amount to be paid if Jessica borrowed a sum of $5750 at 9% simple interest for 8 years.

(6) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $8568 to clear the loan, then find the time period of the loan.

(7) Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $8772 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if Joseph borrowed a sum of $5700 at 6% simple interest for 7 years.

(9) What amount will be due after 2 years if David borrowed a sum of $3200 at a 5% simple interest?

(10) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 7% simple interest?