Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 2% simple interest.


Correct Answer  $6372

Solution And Explanation

Solution

Given,

Principal (P) = $5400

Rate of Simple Interest (SI) = 2%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5400 × 2% × 9

= $5400 ×2/100 × 9

= 5400 × 2 × 9/100

= 10800 × 9/100

= 97200/100

= $972

Thus, Simple Interest = $972

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 = $5400 + $972

= $6372

Thus, Amount to be paid = $6372 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 = $5400

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 9 years

Thus, Amount (A)

= $5400 + ($5400 × 2% × 9)

= $5400 + ($5400 ×2/100 × 9)

= $5400 + (5400 × 2 × 9/100)

= $5400 + (10800 × 9/100)

= $5400 + (97200/100)

= $5400 + $972 = $6372

Thus, Amount (A) to be paid = $6372 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = 2/100

∴ For $5400, the simple interest in 1 year

= 2/100 × 5400

= 2 × 5400/100

= 10800/100 = $108

Thus, simple interest for 1 year = $108

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $108 × 9 = $972

Thus, Simple Interest (SI) = $972

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5400 + $972

= $6372

Thus, Amount to be paid = $6372 Answer


Similar Questions

(1) Find the amount to be paid if Karen borrowed a sum of $5950 at 8% simple interest for 8 years.

(2) Linda had to pay $3852.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) Mary took a loan of $4100 at the rate of 10% simple interest per annum. If he paid an amount of $7380 to clear the loan, then find the time period of the loan.

(4) If David borrowed $3400 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(5) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 2% simple interest.

(6) Richard had to pay $4032 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(7) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 2% simple interest for 8 years.

(8) What amount will be due after 2 years if Joseph borrowed a sum of $3350 at a 7% simple interest?

(9) 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.

(10) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9088 to clear the loan, then find the time period of the loan.


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