Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 4% simple interest.


Correct Answer  $6800

Solution And Explanation

Solution

Given,

Principal (P) = $5000

Rate of Simple Interest (SI) = 4%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $5000 × 4% × 9

= $5000 ×4/100 × 9

= 5000 × 4 × 9/100

= 20000 × 9/100

= 180000/100

= $1800

Thus, Simple Interest = $1800

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 = $5000 + $1800

= $6800

Thus, Amount to be paid = $6800 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 = $5000

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 9 years

Thus, Amount (A)

= $5000 + ($5000 × 4% × 9)

= $5000 + ($5000 ×4/100 × 9)

= $5000 + (5000 × 4 × 9/100)

= $5000 + (20000 × 9/100)

= $5000 + (180000/100)

= $5000 + $1800 = $6800

Thus, Amount (A) to be paid = $6800 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = 4/100

∴ For $5000, the simple interest in 1 year

= 4/100 × 5000

= 4 × 5000/100

= 20000/100 = $200

Thus, simple interest for 1 year = $200

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $200 × 9 = $1800

Thus, Simple Interest (SI) = $1800

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5000 + $1800

= $6800

Thus, Amount to be paid = $6800 Answer


Similar Questions

(1) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 8% simple interest?

(2) What amount does William have to pay after 5 years if he takes a loan of $3500 at 8% simple interest?

(3) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 3% simple interest?

(4) Find the amount to be paid if Richard borrowed a sum of $5600 at 9% simple interest for 7 years.

(5) If Richard borrowed $3600 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(6) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.

(7) Find the amount to be paid if Robert borrowed a sum of $5100 at 9% simple interest for 7 years.

(8) Linda took a loan of $4700 at the rate of 6% simple interest per annum. If he paid an amount of $6392 to clear the loan, then find the time period of the loan.

(9) Donald took a loan of $7000 at the rate of 9% simple interest per annum. If he paid an amount of $13300 to clear the loan, then find the time period of the loan.

(10) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.


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