Simple Interest
MCQs Math


Question:     Find the amount to be paid if Christopher borrowed a sum of $6000 at 8% simple interest for 7 years.


Correct Answer  $9360

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 8%

Time (t) = 7 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) = $6000 × 8% × 7

= $6000 ×8/100 × 7

= 6000 × 8 × 7/100

= 48000 × 7/100

= 336000/100

= $3360

Thus, Simple Interest = $3360

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 + $3360

= $9360

Thus, Amount to be paid = $9360 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) = 8%

And, Time (t) = 7 years

Thus, Amount (A)

= $6000 + ($6000 × 8% × 7)

= $6000 + ($6000 ×8/100 × 7)

= $6000 + (6000 × 8 × 7/100)

= $6000 + (48000 × 7/100)

= $6000 + (336000/100)

= $6000 + $3360 = $9360

Thus, Amount (A) to be paid = $9360 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 $6000, the simple interest in 1 year

= 8/100 × 6000

= 8 × 6000/100

= 48000/100 = $480

Thus, simple interest for 1 year = $480

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $480 × 7 = $3360

Thus, Simple Interest (SI) = $3360

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $3360

= $9360

Thus, Amount to be paid = $9360 Answer


Similar Questions

(1) James took a loan of $4000 at the rate of 7% simple interest per annum. If he paid an amount of $5680 to clear the loan, then find the time period of the loan.

(2) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $7084 to clear the loan, then find the time period of the loan.

(3) In how much time a principal of $3150 will amount to $3465 at a simple interest of 5% per annum?

(4) Find the amount to be paid if Mary borrowed a sum of $5050 at 5% simple interest for 8 years.

(5) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 3% simple interest.

(6) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 6% simple interest.

(7) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 4% simple interest.

(8) If Steven paid $5152 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) Emily had to pay $5177.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) Daniel took a loan of $6200 at the rate of 6% simple interest per annum. If he paid an amount of $8432 to clear the loan, then find the time period of the loan.


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