Simple Interest
MCQs Math


Question:     Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 6% simple interest.


Correct Answer  $8160

Solution And Explanation

Solution

Given,

Principal (P) = $5100

Rate of Simple Interest (SI) = 6%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $5100 × 6% × 10

= $5100 ×6/100 × 10

= 5100 × 6 × 10/100

= 30600 × 10/100

= 306000/100

= $3060

Thus, Simple Interest = $3060

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 = $5100 + $3060

= $8160

Thus, Amount to be paid = $8160 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 = $5100

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 10 years

Thus, Amount (A)

= $5100 + ($5100 × 6% × 10)

= $5100 + ($5100 ×6/100 × 10)

= $5100 + (5100 × 6 × 10/100)

= $5100 + (30600 × 10/100)

= $5100 + (306000/100)

= $5100 + $3060 = $8160

Thus, Amount (A) to be paid = $8160 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $5100, the simple interest in 1 year

= 6/100 × 5100

= 6 × 5100/100

= 30600/100 = $306

Thus, simple interest for 1 year = $306

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $306 × 10 = $3060

Thus, Simple Interest (SI) = $3060

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5100 + $3060

= $8160

Thus, Amount to be paid = $8160 Answer


Similar Questions

(1) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $9348 to clear the loan, then find the time period of the loan.

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

(3) Calculate the amount due if Michael borrowed a sum of $3300 at 10% simple interest for 3 years.

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 5% simple interest?

(5) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $9672 to clear the loan, then find the time period of the loan.

(6) What amount does James have to pay after 5 years if he takes a loan of $3000 at 9% simple interest?

(7) Find the amount to be paid if James borrowed a sum of $5000 at 6% simple interest for 8 years.

(8) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $7396 to clear the loan, then find the time period of the loan.

(9) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 4% simple interest?

(10) Karen took a loan of $5900 at the rate of 7% simple interest per annum. If he paid an amount of $9617 to clear the loan, then find the time period of the loan.


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