Simple Interest
MCQs Math


Question:     Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 8 years.


Correct Answer  $8214

Solution And Explanation

Solution

Given,

Principal (P) = $5550

Rate of Simple Interest (SI) = 6%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $5550 × 6% × 8

= $5550 ×6/100 × 8

= 5550 × 6 × 8/100

= 33300 × 8/100

= 266400/100

= $2664

Thus, Simple Interest = $2664

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 = $5550 + $2664

= $8214

Thus, Amount to be paid = $8214 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 = $5550

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 8 years

Thus, Amount (A)

= $5550 + ($5550 × 6% × 8)

= $5550 + ($5550 ×6/100 × 8)

= $5550 + (5550 × 6 × 8/100)

= $5550 + (33300 × 8/100)

= $5550 + (266400/100)

= $5550 + $2664 = $8214

Thus, Amount (A) to be paid = $8214 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $5550, the simple interest in 1 year

= 6/100 × 5550

= 6 × 5550/100

= 33300/100 = $333

Thus, simple interest for 1 year = $333

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $333 × 8 = $2664

Thus, Simple Interest (SI) = $2664

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5550 + $2664

= $8214

Thus, Amount to be paid = $8214 Answer


Similar Questions

(1) Christopher took a loan of $6000 at the rate of 6% simple interest per annum. If he paid an amount of $9240 to clear the loan, then find the time period of the loan.

(2) How much loan did Jeffrey borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9750 to clear it?

(3) If Michael paid $3564 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(4) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.

(5) If Betty paid $4590 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(6) If Andrew paid $5376 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(7) How much loan did Jessica borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6325 to clear it?

(8) Lisa had to pay $4414.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) Mark took a loan of $6800 at the rate of 9% simple interest per annum. If he paid an amount of $12920 to clear the loan, then find the time period of the loan.

(10) In how much time a principal of $3150 will amount to $3465 at a simple interest of 2% per annum?


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