Simple Interest
MCQs Math


Question:     Find the amount to be paid if Linda borrowed a sum of $5350 at 8% simple interest for 8 years.


Correct Answer  $8774

Solution And Explanation

Solution

Given,

Principal (P) = $5350

Rate of Simple Interest (SI) = 8%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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 × 8% × 8

= $5350 ×8/100 × 8

= 5350 × 8 × 8/100

= 42800 × 8/100

= 342400/100

= $3424

Thus, Simple Interest = $3424

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 + $3424

= $8774

Thus, Amount to be paid = $8774 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) = 8%

And, Time (t) = 8 years

Thus, Amount (A)

= $5350 + ($5350 × 8% × 8)

= $5350 + ($5350 ×8/100 × 8)

= $5350 + (5350 × 8 × 8/100)

= $5350 + (42800 × 8/100)

= $5350 + (342400/100)

= $5350 + $3424 = $8774

Thus, Amount (A) to be paid = $8774 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $5350, the simple interest in 1 year

= 8/100 × 5350

= 8 × 5350/100

= 42800/100 = $428

Thus, simple interest for 1 year = $428

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $428 × 8 = $3424

Thus, Simple Interest (SI) = $3424

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5350 + $3424

= $8774

Thus, Amount to be paid = $8774 Answer


Similar Questions

(1) Calculate the amount due if Sarah borrowed a sum of $3850 at 9% simple interest for 3 years.

(2) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7980 to clear it?

(3) Calculate the amount due if Mary borrowed a sum of $3050 at 2% simple interest for 3 years.

(4) Calculate the amount due if William borrowed a sum of $3500 at 4% simple interest for 3 years.

(5) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 10% simple interest for 7 years.

(6) Christopher took a loan of $6000 at the rate of 7% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 3% simple interest.

(8) How much loan did Timothy borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8880 to clear it?

(9) Calculate the amount due if Barbara borrowed a sum of $3550 at 3% simple interest for 4 years.

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


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