Simple Interest
MCQs Math


Question:     What amount does Michael have to pay after 5 years if he takes a loan of $3300 at 10% simple interest?


Correct Answer  $4950

Solution And Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 10%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3300 × 10% × 5

= $3300 ×10/100 × 5

= 3300 × 10 × 5/100

= 33000 × 5/100

= 165000/100

= $1650

Thus, Simple Interest = $1650

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 = $3300 + $1650

= $4950

Thus, Amount to be paid = $4950 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 = $3300

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 5 years

Thus, Amount (A)

= $3300 + ($3300 × 10% × 5)

= $3300 + ($3300 ×10/100 × 5)

= $3300 + (3300 × 10 × 5/100)

= $3300 + (33000 × 5/100)

= $3300 + (165000/100)

= $3300 + $1650 = $4950

Thus, Amount (A) to be paid = $4950 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $3300, the simple interest in 1 year

= 10/100 × 3300

= 10 × 3300/100

= 33000/100 = $330

Thus, simple interest for 1 year = $330

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $330 × 5 = $1650

Thus, Simple Interest (SI) = $1650

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $1650

= $4950

Thus, Amount to be paid = $4950 Answer


Similar Questions

(1) Calculate the amount due if Richard borrowed a sum of $3600 at 10% simple interest for 3 years.

(2) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $10000 to clear the loan, then find the time period of the loan.

(3) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 5% simple interest?

(4) Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 8 years.

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

(6) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $9310 to clear the loan, then find the time period of the loan.

(7) Barbara had to pay $3763 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

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

(9) Find the amount to be paid if Patricia borrowed a sum of $5150 at 9% simple interest for 8 years.

(10) How much loan did Brian borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9000 to clear it?


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