Simple Interest
MCQs Math


Question:     Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 7 years.


Correct Answer  $7881

Solution And Explanation

Solution

Given,

Principal (P) = $5550

Rate of Simple Interest (SI) = 6%

Time (t) = 7 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% × 7

= $5550 ×6/100 × 7

= 5550 × 6 × 7/100

= 33300 × 7/100

= 233100/100

= $2331

Thus, Simple Interest = $2331

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 + $2331

= $7881

Thus, Amount to be paid = $7881 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) = 7 years

Thus, Amount (A)

= $5550 + ($5550 × 6% × 7)

= $5550 + ($5550 ×6/100 × 7)

= $5550 + (5550 × 6 × 7/100)

= $5550 + (33300 × 7/100)

= $5550 + (233100/100)

= $5550 + $2331 = $7881

Thus, Amount (A) to be paid = $7881 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 7 years

= Simple interest for 1 year × 7

= $333 × 7 = $2331

Thus, Simple Interest (SI) = $2331

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5550 + $2331

= $7881

Thus, Amount to be paid = $7881 Answer


Similar Questions

(1) Sandra took a loan of $6900 at the rate of 6% simple interest per annum. If he paid an amount of $9798 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Christopher borrowed a sum of $4000 at 7% simple interest for 4 years.

(3) Linda took a loan of $4700 at the rate of 10% simple interest per annum. If he paid an amount of $9400 to clear the loan, then find the time period of the loan.

(4) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 6% simple interest?

(5) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 4% simple interest.

(6) Find the amount to be paid if Susan borrowed a sum of $5650 at 2% simple interest for 7 years.

(7) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.

(8) Margaret took a loan of $6700 at the rate of 6% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Jessica borrowed a sum of $3750 at 2% simple interest for 3 years.

(10) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.


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