Simple Interest
MCQs Math


Question:     Find the amount to be paid if Christopher borrowed a sum of $6000 at 6% simple interest for 8 years.


Correct Answer  $8880

Solution And Explanation

Solution

Given,

Principal (P) = $6000

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) = $6000 × 6% × 8

= $6000 ×6/100 × 8

= 6000 × 6 × 8/100

= 36000 × 8/100

= 288000/100

= $2880

Thus, Simple Interest = $2880

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 = $6000 + $2880

= $8880

Thus, Amount to be paid = $8880 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 = $6000

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

And, Time (t) = 8 years

Thus, Amount (A)

= $6000 + ($6000 × 6% × 8)

= $6000 + ($6000 ×6/100 × 8)

= $6000 + (6000 × 6 × 8/100)

= $6000 + (36000 × 8/100)

= $6000 + (288000/100)

= $6000 + $2880 = $8880

Thus, Amount (A) to be paid = $8880 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 $6000, the simple interest in 1 year

= 6/100 × 6000

= 6 × 6000/100

= 36000/100 = $360

Thus, simple interest for 1 year = $360

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $360 × 8 = $2880

Thus, Simple Interest (SI) = $2880

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $2880

= $8880

Thus, Amount to be paid = $8880 Answer


Similar Questions

(1) Calculate the amount due if Michael borrowed a sum of $3300 at 8% simple interest for 3 years.

(2) Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if David borrowed a sum of $3400 at 6% simple interest for 4 years.

(4) Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $10560 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 3% simple interest.

(6) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 5% simple interest.

(7) Calculate the amount due if Charles borrowed a sum of $3900 at 4% simple interest for 3 years.

(8) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $11247 to clear the loan, then find the time period of the loan.

(9) What amount does John have to pay after 5 years if he takes a loan of $3200 at 4% simple interest?

(10) In how much time a principal of $3050 will amount to $3507.5 at a simple interest of 3% per annum?


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