Simple Interest
MCQs Math


Question:     Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 2% simple interest.


Correct Answer  $6600

Solution And Explanation

Solution

Given,

Principal (P) = $5500

Rate of Simple Interest (SI) = 2%

Time (t) = 10 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) = $5500 × 2% × 10

= $5500 ×2/100 × 10

= 5500 × 2 × 10/100

= 11000 × 10/100

= 110000/100

= $1100

Thus, Simple Interest = $1100

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 = $5500 + $1100

= $6600

Thus, Amount to be paid = $6600 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 = $5500

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5500 + ($5500 × 2% × 10)

= $5500 + ($5500 ×2/100 × 10)

= $5500 + (5500 × 2 × 10/100)

= $5500 + (11000 × 10/100)

= $5500 + (110000/100)

= $5500 + $1100 = $6600

Thus, Amount (A) to be paid = $6600 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 $5500, the simple interest in 1 year

= 2/100 × 5500

= 2 × 5500/100

= 11000/100 = $110

Thus, simple interest for 1 year = $110

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $110 × 10 = $1100

Thus, Simple Interest (SI) = $1100

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5500 + $1100

= $6600

Thus, Amount to be paid = $6600 Answer


Similar Questions

(1) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 3% simple interest.

(2) Find the amount to be paid if Richard borrowed a sum of $5600 at 6% simple interest for 7 years.

(3) Find the amount to be paid if John borrowed a sum of $5200 at 6% simple interest for 8 years.

(4) If Thomas borrowed $3800 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(5) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6683 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 9% simple interest.

(7) How much loan did Dorothy borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7975 to clear it?

(8) If Sarah paid $4158 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(9) If Robert paid $3720 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(10) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9394 to clear the loan, then find the time period of the loan.


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