Simple Interest
MCQs Math


Question:     Calculate the amount due if Mary borrowed a sum of $3050 at 6% simple interest for 3 years.


Correct Answer  $3599

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 6%

Time (t) = 3 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3050 × 6% × 3

= $3050 ×6/100 × 3

= 3050 × 6 × 3/100

= 18300 × 3/100

= 54900/100

= $549

Thus, Simple Interest = $549

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 = $3050 + $549

= $3599

Thus, Amount to be paid = $3599 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 = $3050

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 3 years

Thus, Amount (A)

= $3050 + ($3050 × 6% × 3)

= $3050 + ($3050 ×6/100 × 3)

= $3050 + (3050 × 6 × 3/100)

= $3050 + (18300 × 3/100)

= $3050 + (54900/100)

= $3050 + $549 = $3599

Thus, Amount (A) to be paid = $3599 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3050, the simple interest in 1 year

= 6/100 × 3050

= 6 × 3050/100

= 18300/100 = $183

Thus, simple interest for 1 year = $183

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $183 × 3 = $549

Thus, Simple Interest (SI) = $549

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $549

= $3599

Thus, Amount to be paid = $3599 Answer


Similar Questions

(1) Sandra took a loan of $6900 at the rate of 9% simple interest per annum. If he paid an amount of $10626 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if John borrowed a sum of $5200 at 4% simple interest for 7 years.

(3) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 6% simple interest?

(4) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 2% simple interest.

(5) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $7498 to clear the loan, then find the time period of the loan.

(6) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $7224 to clear the loan, then find the time period of the loan.

(7) Sarah took a loan of $5700 at the rate of 6% simple interest per annum. If he paid an amount of $8094 to clear the loan, then find the time period of the loan.

(8) What amount does John have to pay after 6 years if he takes a loan of $3200 at 10% simple interest?

(9) Find the amount to be paid if David borrowed a sum of $5400 at 6% simple interest for 7 years.

(10) James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $6400 to clear the loan, then find the time period of the loan.


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