Simple Interest
MCQs Math


Question:     What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 9% simple interest?


Correct Answer  $5544

Solution And Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3600 × 9% × 6

= $3600 ×9/100 × 6

= 3600 × 9 × 6/100

= 32400 × 6/100

= 194400/100

= $1944

Thus, Simple Interest = $1944

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 = $3600 + $1944

= $5544

Thus, Amount to be paid = $5544 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 = $3600

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3600 + ($3600 × 9% × 6)

= $3600 + ($3600 ×9/100 × 6)

= $3600 + (3600 × 9 × 6/100)

= $3600 + (32400 × 6/100)

= $3600 + (194400/100)

= $3600 + $1944 = $5544

Thus, Amount (A) to be paid = $5544 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3600, the simple interest in 1 year

= 9/100 × 3600

= 9 × 3600/100

= 32400/100 = $324

Thus, simple interest for 1 year = $324

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $324 × 6 = $1944

Thus, Simple Interest (SI) = $1944

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1944

= $5544

Thus, Amount to be paid = $5544 Answer


Similar Questions

(1) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 7% simple interest.

(2) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 8% simple interest.

(3) Nancy took a loan of $6300 at the rate of 7% simple interest per annum. If he paid an amount of $10710 to clear the loan, then find the time period of the loan.

(4) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 3% simple interest?

(5) Michael took a loan of $4600 at the rate of 7% simple interest per annum. If he paid an amount of $6854 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if David borrowed a sum of $5400 at 5% simple interest for 8 years.

(7) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 10% simple interest?

(8) Calculate the amount due if Thomas borrowed a sum of $3800 at 4% simple interest for 3 years.

(9) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $10260 to clear the loan, then find the time period of the loan.

(10) If Patricia paid $3528 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.


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