Simple Interest
MCQs Math


Question:     What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 9% simple interest?


Correct Answer  $3599

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 9%

Time (t) = 2 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) = $3050 × 9% × 2

= $3050 ×9/100 × 2

= 3050 × 9 × 2/100

= 27450 × 2/100

= 54900/100

= $549

Thus, Simple Interest = $549

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 = $3050 + $549

= $3599

Thus, Amount to be paid = $3599 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 = $3050

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3050 + ($3050 × 9% × 2)

= $3050 + ($3050 ×9/100 × 2)

= $3050 + (3050 × 9 × 2/100)

= $3050 + (27450 × 2/100)

= $3050 + (54900/100)

= $3050 + $549 = $3599

Thus, Amount (A) to be paid = $3599 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 $3050, the simple interest in 1 year

= 9/100 × 3050

= 9 × 3050/100

= 27450/100 = $274.5

Thus, simple interest for 1 year = $274.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $274.5 × 2 = $549

Thus, Simple Interest (SI) = $549

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $549

= $3599

Thus, Amount to be paid = $3599 Answer


Similar Questions

(1) If David paid $3808 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(2) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 8% simple interest?

(3) Find the amount to be paid if David borrowed a sum of $5400 at 2% simple interest for 8 years.

(4) What amount does David have to pay after 6 years if he takes a loan of $3400 at 10% simple interest?

(5) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 8 years.

(6) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 4% simple interest?

(7) Find the amount to be paid if Barbara borrowed a sum of $5550 at 8% simple interest for 8 years.

(8) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.

(9) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $10608 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 6% simple interest.


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