Simple Interest
MCQs Math


Question:     If Sarah borrowed $3850 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.


Correct Answer  $4081

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 3%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $3850 × 3% × 2

= $3850 ×3/100 × 2

= 3850 × 3 × 2/100

= 11550 × 2/100

= 23100/100

= $231

Thus, Simple Interest = $231

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 = $3850 + $231

= $4081

Thus, Amount to be paid = $4081 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 = $3850

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 2 years

Thus, Amount (A)

= $3850 + ($3850 × 3% × 2)

= $3850 + ($3850 ×3/100 × 2)

= $3850 + (3850 × 3 × 2/100)

= $3850 + (11550 × 2/100)

= $3850 + (23100/100)

= $3850 + $231 = $4081

Thus, Amount (A) to be paid = $4081 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3850, the simple interest in 1 year

= 3/100 × 3850

= 3 × 3850/100

= 11550/100 = $115.5

Thus, simple interest for 1 year = $115.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $115.5 × 2 = $231

Thus, Simple Interest (SI) = $231

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $231

= $4081

Thus, Amount to be paid = $4081 Answer


Similar Questions

(1) Mark took a loan of $6800 at the rate of 6% simple interest per annum. If he paid an amount of $9248 to clear the loan, then find the time period of the loan.

(2) Joseph took a loan of $5400 at the rate of 10% simple interest per annum. If he paid an amount of $9720 to clear the loan, then find the time period of the loan.

(3) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 8% simple interest?

(4) Find the amount to be paid if Jessica borrowed a sum of $5750 at 3% simple interest for 7 years.

(5) John had to pay $3680 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(6) If Michelle paid $5742 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(7) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8000 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Richard borrowed a sum of $3600 at 2% simple interest for 4 years.

(9) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $9394 to clear the loan, then find the time period of the loan.

(10) If Matthew paid $4872 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.


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