Simple Interest
MCQs Math


Question:     Find the amount to be paid if Christopher borrowed a sum of $6000 at 3% simple interest for 8 years.


Correct Answer  $7440

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 3%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 8

= $6000 ×3/100 × 8

= 6000 × 3 × 8/100

= 18000 × 8/100

= 144000/100

= $1440

Thus, Simple Interest = $1440

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 + $1440

= $7440

Thus, Amount to be paid = $7440 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) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $6000 + ($6000 × 3% × 8)

= $6000 + ($6000 ×3/100 × 8)

= $6000 + (6000 × 3 × 8/100)

= $6000 + (18000 × 8/100)

= $6000 + (144000/100)

= $6000 + $1440 = $7440

Thus, Amount (A) to be paid = $7440 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $6000, the simple interest in 1 year

= 3/100 × 6000

= 3 × 6000/100

= 18000/100 = $180

Thus, simple interest for 1 year = $180

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $180 × 8 = $1440

Thus, Simple Interest (SI) = $1440

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $1440

= $7440

Thus, Amount to be paid = $7440 Answer


Similar Questions

(1) If Elizabeth paid $3726 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

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

(3) If Karen paid $4582 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(4) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 10% simple interest?

(5) Susan took a loan of $5300 at the rate of 10% simple interest per annum. If he paid an amount of $8480 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Jennifer borrowed a sum of $3250 at 5% simple interest for 3 years.

(7) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 5% simple interest?

(8) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 6% simple interest.

(9) What amount does John have to pay after 6 years if he takes a loan of $3200 at 9% simple interest?

(10) Calculate the amount due if Joseph borrowed a sum of $3700 at 4% simple interest for 3 years.


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