Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 10% simple interest.


Correct Answer  $10165

Solution And Explanation

Solution

Given,

Principal (P) = $5350

Rate of Simple Interest (SI) = 10%

Time (t) = 9 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) = $5350 × 10% × 9

= $5350 ×10/100 × 9

= 5350 × 10 × 9/100

= 53500 × 9/100

= 481500/100

= $4815

Thus, Simple Interest = $4815

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 = $5350 + $4815

= $10165

Thus, Amount to be paid = $10165 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 = $5350

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

And, Time (t) = 9 years

Thus, Amount (A)

= $5350 + ($5350 × 10% × 9)

= $5350 + ($5350 ×10/100 × 9)

= $5350 + (5350 × 10 × 9/100)

= $5350 + (53500 × 9/100)

= $5350 + (481500/100)

= $5350 + $4815 = $10165

Thus, Amount (A) to be paid = $10165 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 $5350, the simple interest in 1 year

= 10/100 × 5350

= 10 × 5350/100

= 53500/100 = $535

Thus, simple interest for 1 year = $535

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $535 × 9 = $4815

Thus, Simple Interest (SI) = $4815

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $4815

= $10165

Thus, Amount to be paid = $10165 Answer


Similar Questions

(1) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11160 to clear the loan, then find the time period of the loan.

(2) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $8024 to clear the loan, then find the time period of the loan.

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

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

(5) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 8% simple interest.

(7) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $7020 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3200 will amount to $3520 at a simple interest of 5% per annum?

(9) Calculate the amount due if Linda borrowed a sum of $3350 at 6% simple interest for 4 years.

(10) How much loan did David borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5940 to clear it?


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