Simple Interest
MCQs Math


Question:     What amount does Christopher have to pay after 5 years if he takes a loan of $4000 at 8% simple interest?


Correct Answer  $5600

Solution And Explanation

Solution

Given,

Principal (P) = $4000

Rate of Simple Interest (SI) = 8%

Time (t) = 5 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) = $4000 × 8% × 5

= $4000 ×8/100 × 5

= 4000 × 8 × 5/100

= 32000 × 5/100

= 160000/100

= $1600

Thus, Simple Interest = $1600

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 = $4000 + $1600

= $5600

Thus, Amount to be paid = $5600 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 = $4000

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 5 years

Thus, Amount (A)

= $4000 + ($4000 × 8% × 5)

= $4000 + ($4000 ×8/100 × 5)

= $4000 + (4000 × 8 × 5/100)

= $4000 + (32000 × 5/100)

= $4000 + (160000/100)

= $4000 + $1600 = $5600

Thus, Amount (A) to be paid = $5600 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 $4000, the simple interest in 1 year

= 8/100 × 4000

= 8 × 4000/100

= 32000/100 = $320

Thus, simple interest for 1 year = $320

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $320 × 5 = $1600

Thus, Simple Interest (SI) = $1600

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $4000 + $1600

= $5600

Thus, Amount to be paid = $5600 Answer


Similar Questions

(1) If Paul paid $5640 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(2) Calculate the amount due if Karen borrowed a sum of $3950 at 6% simple interest for 4 years.

(3) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $10758 to clear the loan, then find the time period of the loan.

(4) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8312.5 to clear it?

(5) Christopher had to pay $4480 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(6) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 2% simple interest?

(7) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 10% simple interest.

(8) If Betty paid $4930 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(9) Michael took a loan of $4600 at the rate of 10% simple interest per annum. If he paid an amount of $7360 to clear the loan, then find the time period of the loan.

(10) Donald took a loan of $7000 at the rate of 10% simple interest per annum. If he paid an amount of $12600 to clear the loan, then find the time period of the loan.


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