Simple Interest
MCQs Math


Question:     If Susan borrowed $3650 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.


Correct Answer  $3869

Solution And Explanation

Solution

Given,

Principal (P) = $3650

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) = $3650 × 3% × 2

= $3650 ×3/100 × 2

= 3650 × 3 × 2/100

= 10950 × 2/100

= 21900/100

= $219

Thus, Simple Interest = $219

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 = $3650 + $219

= $3869

Thus, Amount to be paid = $3869 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 = $3650

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3650 + ($3650 × 3% × 2)

= $3650 + ($3650 ×3/100 × 2)

= $3650 + (3650 × 3 × 2/100)

= $3650 + (10950 × 2/100)

= $3650 + (21900/100)

= $3650 + $219 = $3869

Thus, Amount (A) to be paid = $3869 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 $3650, the simple interest in 1 year

= 3/100 × 3650

= 3 × 3650/100

= 10950/100 = $109.5

Thus, simple interest for 1 year = $109.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $109.5 × 2 = $219

Thus, Simple Interest (SI) = $219

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3650 + $219

= $3869

Thus, Amount to be paid = $3869 Answer


Similar Questions

(1) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 5% simple interest.

(2) Find the amount to be paid if Christopher borrowed a sum of $6000 at 5% simple interest for 8 years.

(3) Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 6% simple interest.

(4) Find the amount to be paid if Barbara borrowed a sum of $5550 at 2% simple interest for 8 years.

(5) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $8008 to clear the loan, then find the time period of the loan.

(6) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $9880 to clear the loan, then find the time period of the loan.

(7) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 4% simple interest?

(8) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 4% simple interest.

(9) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $9768 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 2% simple interest.


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