Simple Interest
MCQs Math


Question:     Find the amount to be paid if Christopher borrowed a sum of $6000 at 4% simple interest for 8 years.


Correct Answer  $7920

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 4%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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 × 4% × 8

= $6000 ×4/100 × 8

= 6000 × 4 × 8/100

= 24000 × 8/100

= 192000/100

= $1920

Thus, Simple Interest = $1920

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 + $1920

= $7920

Thus, Amount to be paid = $7920 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) = 4%

And, Time (t) = 8 years

Thus, Amount (A)

= $6000 + ($6000 × 4% × 8)

= $6000 + ($6000 ×4/100 × 8)

= $6000 + (6000 × 4 × 8/100)

= $6000 + (24000 × 8/100)

= $6000 + (192000/100)

= $6000 + $1920 = $7920

Thus, Amount (A) to be paid = $7920 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = 4/100

∴ For $6000, the simple interest in 1 year

= 4/100 × 6000

= 4 × 6000/100

= 24000/100 = $240

Thus, simple interest for 1 year = $240

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $240 × 8 = $1920

Thus, Simple Interest (SI) = $1920

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $1920

= $7920

Thus, Amount to be paid = $7920 Answer


Similar Questions

(1) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $13800 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 10% simple interest?

(3) How much loan did Barbara borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $6937.5 to clear it?

(4) Calculate the amount due if Thomas borrowed a sum of $3800 at 6% simple interest for 3 years.

(5) Calculate the amount due if Charles borrowed a sum of $3900 at 2% simple interest for 3 years.

(6) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 7% simple interest?

(7) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 3 years.

(8) Thomas took a loan of $5600 at the rate of 6% simple interest per annum. If he paid an amount of $7952 to clear the loan, then find the time period of the loan.

(9) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 4% simple interest?

(10) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $8732 to clear the loan, then find the time period of the loan.


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©