Simple Interest
MCQs Math


Question:     What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 10% simple interest?


Correct Answer  $5280

Solution And Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 10%

Time (t) = 6 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% × 6

= $3300 ×10/100 × 6

= 3300 × 10 × 6/100

= 33000 × 6/100

= 198000/100

= $1980

Thus, Simple Interest = $1980

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 + $1980

= $5280

Thus, Amount to be paid = $5280 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) = 6 years

Thus, Amount (A)

= $3300 + ($3300 × 10% × 6)

= $3300 + ($3300 ×10/100 × 6)

= $3300 + (3300 × 10 × 6/100)

= $3300 + (33000 × 6/100)

= $3300 + (198000/100)

= $3300 + $1980 = $5280

Thus, Amount (A) to be paid = $5280 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 6 years

= Simple interest for 1 year × 6

= $330 × 6 = $1980

Thus, Simple Interest (SI) = $1980

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $1980

= $5280

Thus, Amount to be paid = $5280 Answer


Similar Questions

(1) Find the amount to be paid if Susan borrowed a sum of $5650 at 5% simple interest for 7 years.

(2) If John paid $3456 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(3) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 5% simple interest.

(4) How much loan did Margaret borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7302.5 to clear it?

(5) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 7% simple interest?

(6) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $10836 to clear the loan, then find the time period of the loan.

(7) Patricia took a loan of $4300 at the rate of 9% simple interest per annum. If he paid an amount of $8170 to clear the loan, then find the time period of the loan.

(8) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $9050 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Joseph borrowed a sum of $3700 at 10% simple interest for 4 years.

(10) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 3% simple interest?


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