Simple Interest
MCQs Math


Question:     Find the amount to be paid if Thomas borrowed a sum of $5800 at 10% simple interest for 7 years.


Correct Answer  $9860

Solution And Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 10%

Time (t) = 7 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% × 7

= $5800 ×10/100 × 7

= 5800 × 10 × 7/100

= 58000 × 7/100

= 406000/100

= $4060

Thus, Simple Interest = $4060

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 + $4060

= $9860

Thus, Amount to be paid = $9860 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) = 7 years

Thus, Amount (A)

= $5800 + ($5800 × 10% × 7)

= $5800 + ($5800 ×10/100 × 7)

= $5800 + (5800 × 10 × 7/100)

= $5800 + (58000 × 7/100)

= $5800 + (406000/100)

= $5800 + $4060 = $9860

Thus, Amount (A) to be paid = $9860 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 7 years

= Simple interest for 1 year × 7

= $580 × 7 = $4060

Thus, Simple Interest (SI) = $4060

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $4060

= $9860

Thus, Amount to be paid = $9860 Answer


Similar Questions

(1) What amount will be due after 2 years if James borrowed a sum of $3000 at a 4% simple interest?

(2) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 8% simple interest?

(3) Calculate the amount due if Christopher borrowed a sum of $4000 at 5% simple interest for 4 years.

(4) Find the amount to be paid if Michael borrowed a sum of $5300 at 9% simple interest for 8 years.

(5) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 2% simple interest.

(6) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $7544 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due if Richard borrowed a sum of $3600 at 2% simple interest for 3 years.

(8) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $9086 to clear the loan, then find the time period of the loan.

(9) Betty took a loan of $6500 at the rate of 6% simple interest per annum. If he paid an amount of $8840 to clear the loan, then find the time period of the loan.

(10) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 8% simple interest?


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