Simple Interest
MCQs Math


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


Correct Answer  $6820

Solution And Explanation

Solution

Given,

Principal (P) = $5500

Rate of Simple Interest (SI) = 3%

Time (t) = 8 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) = $5500 × 3% × 8

= $5500 ×3/100 × 8

= 5500 × 3 × 8/100

= 16500 × 8/100

= 132000/100

= $1320

Thus, Simple Interest = $1320

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 = $5500 + $1320

= $6820

Thus, Amount to be paid = $6820 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 = $5500

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

And, Time (t) = 8 years

Thus, Amount (A)

= $5500 + ($5500 × 3% × 8)

= $5500 + ($5500 ×3/100 × 8)

= $5500 + (5500 × 3 × 8/100)

= $5500 + (16500 × 8/100)

= $5500 + (132000/100)

= $5500 + $1320 = $6820

Thus, Amount (A) to be paid = $6820 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 $5500, the simple interest in 1 year

= 3/100 × 5500

= 3 × 5500/100

= 16500/100 = $165

Thus, simple interest for 1 year = $165

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $165 × 8 = $1320

Thus, Simple Interest (SI) = $1320

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5500 + $1320

= $6820

Thus, Amount to be paid = $6820 Answer


Similar Questions

(1) How much loan did Sharon borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8525 to clear it?

(2) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 6% simple interest?

(3) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 7% simple interest.

(4) James took a loan of $4000 at the rate of 7% simple interest per annum. If he paid an amount of $5960 to clear the loan, then find the time period of the loan.

(5) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 5% simple interest?

(6) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6109 to clear the loan, then find the time period of the loan.

(7) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.

(8) If Christopher borrowed $4000 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(9) If John paid $3840 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(10) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 10% simple interest for 8 years.


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