Simple Interest
MCQs Math


Question:     Calculate the amount due if Barbara borrowed a sum of $3550 at 6% simple interest for 4 years.


Correct Answer  $4402

Solution And Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 6%

Time (t) = 4 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) = $3550 × 6% × 4

= $3550 ×6/100 × 4

= 3550 × 6 × 4/100

= 21300 × 4/100

= 85200/100

= $852

Thus, Simple Interest = $852

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 = $3550 + $852

= $4402

Thus, Amount to be paid = $4402 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 = $3550

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

And, Time (t) = 4 years

Thus, Amount (A)

= $3550 + ($3550 × 6% × 4)

= $3550 + ($3550 ×6/100 × 4)

= $3550 + (3550 × 6 × 4/100)

= $3550 + (21300 × 4/100)

= $3550 + (85200/100)

= $3550 + $852 = $4402

Thus, Amount (A) to be paid = $4402 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 $3550, the simple interest in 1 year

= 6/100 × 3550

= 6 × 3550/100

= 21300/100 = $213

Thus, simple interest for 1 year = $213

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $213 × 4 = $852

Thus, Simple Interest (SI) = $852

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $852

= $4402

Thus, Amount to be paid = $4402 Answer


Similar Questions

(1) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $11008 to clear the loan, then find the time period of the loan.

(2) If Elizabeth paid $4140 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) In how much time a principal of $3100 will amount to $3286 at a simple interest of 2% per annum?

(4) If Susan paid $3942 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(5) If Andrew paid $5184 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(6) Nancy took a loan of $6300 at the rate of 6% simple interest per annum. If he paid an amount of $8568 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 3% simple interest.

(8) How much loan did Jeffrey borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8580 to clear it?

(9) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 9% simple interest?

(10) How much loan did Donald borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7475 to clear it?


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