Simple Interest
MCQs Math


Question:     Find the amount to be paid if Thomas borrowed a sum of $5800 at 10% simple interest for 8 years.


Correct Answer  $10440

Solution And Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 10%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $5800 × 10% × 8

= $5800 ×10/100 × 8

= 5800 × 10 × 8/100

= 58000 × 8/100

= 464000/100

= $4640

Thus, Simple Interest = $4640

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 = $5800 + $4640

= $10440

Thus, Amount to be paid = $10440 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 = $5800

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 8 years

Thus, Amount (A)

= $5800 + ($5800 × 10% × 8)

= $5800 + ($5800 ×10/100 × 8)

= $5800 + (5800 × 10 × 8/100)

= $5800 + (58000 × 8/100)

= $5800 + (464000/100)

= $5800 + $4640 = $10440

Thus, Amount (A) to be paid = $10440 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $5800, the simple interest in 1 year

= 10/100 × 5800

= 10 × 5800/100

= 58000/100 = $580

Thus, simple interest for 1 year = $580

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $580 × 8 = $4640

Thus, Simple Interest (SI) = $4640

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $4640

= $10440

Thus, Amount to be paid = $10440 Answer


Similar Questions

(1) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $8024 to clear the loan, then find the time period of the loan.

(2) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $8600 to clear the loan, then find the time period of the loan.

(3) Find the amount to be paid if Linda borrowed a sum of $5350 at 6% simple interest for 8 years.

(4) John took a loan of $4400 at the rate of 7% simple interest per annum. If he paid an amount of $7480 to clear the loan, then find the time period of the loan.

(5) If Linda paid $3752 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(6) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $7824 to clear the loan, then find the time period of the loan.

(7) Patricia took a loan of $4300 at the rate of 7% simple interest per annum. If he paid an amount of $6106 to clear the loan, then find the time period of the loan.

(8) How much loan did Cynthia borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9540 to clear it?

(9) If Donna paid $5820 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(10) Anthony took a loan of $6600 at the rate of 7% simple interest per annum. If he paid an amount of $11220 to clear the loan, then find the time period of the loan.


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