Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 9% simple interest.


Correct Answer  $10860

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 9%

Time (t) = 9 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) = $6000 × 9% × 9

= $6000 ×9/100 × 9

= 6000 × 9 × 9/100

= 54000 × 9/100

= 486000/100

= $4860

Thus, Simple Interest = $4860

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 = $6000 + $4860

= $10860

Thus, Amount to be paid = $10860 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 = $6000

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

And, Time (t) = 9 years

Thus, Amount (A)

= $6000 + ($6000 × 9% × 9)

= $6000 + ($6000 ×9/100 × 9)

= $6000 + (6000 × 9 × 9/100)

= $6000 + (54000 × 9/100)

= $6000 + (486000/100)

= $6000 + $4860 = $10860

Thus, Amount (A) to be paid = $10860 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 $6000, the simple interest in 1 year

= 9/100 × 6000

= 9 × 6000/100

= 54000/100 = $540

Thus, simple interest for 1 year = $540

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $540 × 9 = $4860

Thus, Simple Interest (SI) = $4860

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $4860

= $10860

Thus, Amount to be paid = $10860 Answer


Similar Questions

(1) John had to pay $3392 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(2) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 6% simple interest?

(3) Calculate the amount due if Jennifer borrowed a sum of $3250 at 8% simple interest for 3 years.

(4) Sarah took a loan of $5700 at the rate of 6% simple interest per annum. If he paid an amount of $7752 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Sarah borrowed a sum of $3850 at 8% simple interest for 4 years.

(6) Mark took a loan of $6800 at the rate of 9% simple interest per annum. If he paid an amount of $11696 to clear the loan, then find the time period of the loan.

(7) Kenneth had to pay $5750 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(8) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 5% simple interest?

(9) Kimberly had to pay $4929 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(10) If Donald paid $5220 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©