Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 3% simple interest?


Correct Answer  $4189

Solution And Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

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

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

= $3550 ×3/100 × 6

= 3550 × 3 × 6/100

= 10650 × 6/100

= 63900/100

= $639

Thus, Simple Interest = $639

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 + $639

= $4189

Thus, Amount to be paid = $4189 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) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3550 + ($3550 × 3% × 6)

= $3550 + ($3550 ×3/100 × 6)

= $3550 + (3550 × 3 × 6/100)

= $3550 + (10650 × 6/100)

= $3550 + (63900/100)

= $3550 + $639 = $4189

Thus, Amount (A) to be paid = $4189 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3550, the simple interest in 1 year

= 3/100 × 3550

= 3 × 3550/100

= 10650/100 = $106.5

Thus, simple interest for 1 year = $106.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $106.5 × 6 = $639

Thus, Simple Interest (SI) = $639

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $639

= $4189

Thus, Amount to be paid = $4189 Answer


Similar Questions

(1) How much loan did Sharon borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8525 to clear it?

(2) Donald had to pay $5175 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 10% simple interest?

(4) Michael took a loan of $4600 at the rate of 10% simple interest per annum. If he paid an amount of $7360 to clear the loan, then find the time period of the loan.

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

(6) If Emily paid $5320 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(7) Calculate the amount due if William borrowed a sum of $3500 at 8% simple interest for 4 years.

(8) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 6% simple interest?

(9) If Michael paid $3696 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(10) In how much time a principal of $3050 will amount to $3416 at a simple interest of 3% per annum?


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