Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 3% simple interest.

Correct Answer  $7670

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 3%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5900 × 3% × 10

= $5900 ׳/₁₀₀ × 10

= ^{5900 × 3 × 10}/₁₀₀

= ^{17700 × 10}/₁₀₀

= ¹⁷⁷⁰⁰⁰/₁₀₀

= $1770

Thus, Simple Interest = $1770

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 = $5900 + $1770

= $7670

Thus, Amount to be paid = $7670 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 = $5900

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 10 years

Thus, Amount (A)

= $5900 + ($5900 × 3% × 10)

= $5900 + ($5900 ׳/₁₀₀ × 10)

= $5900 + (^{5900 × 3 × 10}/₁₀₀)

= $5900 + (^{17700 × 10}/₁₀₀)

= $5900 + (¹⁷⁷⁰⁰⁰/₁₀₀)

= $5900 + $1770 = $7670

Thus, Amount (A) to be paid = $7670 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5900, the simple interest in 1 year

= ³/₁₀₀ × 5900

= ^{3 × 5900}/₁₀₀

= ¹⁷⁷⁰⁰/₁₀₀ = $177

Thus, simple interest for 1 year = $177

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $177 × 10 = $1770

Thus, Simple Interest (SI) = $1770

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $1770

= $7670

Thus, Amount to be paid = $7670 Answer

Similar Questions

(1) Joseph took a loan of $5400 at the rate of 10% simple interest per annum. If he paid an amount of $10800 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 10% simple interest?

(3) How much loan did Jason borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8470 to clear it?

(4) If Kenneth paid $5400 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(5) In how much time a principal of $3050 will amount to $3812.5 at a simple interest of 5% per annum?

(6) John took a loan of $4400 at the rate of 7% simple interest per annum. If he paid an amount of $6556 to clear the loan, then find the time period of the loan.

(7) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 10% simple interest?

(8) Find the amount to be paid if Jessica borrowed a sum of $5750 at 7% simple interest for 7 years.

(9) Betty took a loan of $6500 at the rate of 8% simple interest per annum. If he paid an amount of $10660 to clear the loan, then find the time period of the loan.

(10) Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.