Simple Interest
MCQs Math


Question:     Find the amount to be paid if Richard borrowed a sum of $5600 at 10% simple interest for 8 years.


Correct Answer  $10080

Solution And Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 10%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $5600 × 10% × 8

= $5600 ×10/100 × 8

= 5600 × 10 × 8/100

= 56000 × 8/100

= 448000/100

= $4480

Thus, Simple Interest = $4480

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 = $5600 + $4480

= $10080

Thus, Amount to be paid = $10080 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 = $5600

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 8 years

Thus, Amount (A)

= $5600 + ($5600 × 10% × 8)

= $5600 + ($5600 ×10/100 × 8)

= $5600 + (5600 × 10 × 8/100)

= $5600 + (56000 × 8/100)

= $5600 + (448000/100)

= $5600 + $4480 = $10080

Thus, Amount (A) to be paid = $10080 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $5600, the simple interest in 1 year

= 10/100 × 5600

= 10 × 5600/100

= 56000/100 = $560

Thus, simple interest for 1 year = $560

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $560 × 8 = $4480

Thus, Simple Interest (SI) = $4480

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $4480

= $10080

Thus, Amount to be paid = $10080 Answer


Similar Questions

(1) Calculate the amount due if Robert borrowed a sum of $3100 at 7% simple interest for 4 years.

(2) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6396 to clear the loan, then find the time period of the loan.

(3) If Jennifer borrowed $3250 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(4) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 4% simple interest.

(5) Find the amount to be paid if Mary borrowed a sum of $5050 at 3% simple interest for 7 years.

(6) What amount will be due after 2 years if William borrowed a sum of $3250 at a 6% simple interest?

(7) Linda took a loan of $4700 at the rate of 6% simple interest per annum. If he paid an amount of $6956 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3000 will amount to $3180 at a simple interest of 3% per annum?

(9) Elizabeth took a loan of $4900 at the rate of 7% simple interest per annum. If he paid an amount of $7301 to clear the loan, then find the time period of the loan.

(10) If Mark paid $4752 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.


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