Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 2% simple interest?


Correct Answer  $3976

Solution And Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 2%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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 × 2% × 6

= $3550 ×2/100 × 6

= 3550 × 2 × 6/100

= 7100 × 6/100

= 42600/100

= $426

Thus, Simple Interest = $426

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 + $426

= $3976

Thus, Amount to be paid = $3976 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) = 2%

And, Time (t) = 6 years

Thus, Amount (A)

= $3550 + ($3550 × 2% × 6)

= $3550 + ($3550 ×2/100 × 6)

= $3550 + (3550 × 2 × 6/100)

= $3550 + (7100 × 6/100)

= $3550 + (42600/100)

= $3550 + $426 = $3976

Thus, Amount (A) to be paid = $3976 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = 2/100

∴ For $3550, the simple interest in 1 year

= 2/100 × 3550

= 2 × 3550/100

= 7100/100 = $71

Thus, simple interest for 1 year = $71

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $71 × 6 = $426

Thus, Simple Interest (SI) = $426

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $426

= $3976

Thus, Amount to be paid = $3976 Answer


Similar Questions

(1) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 6% simple interest.

(2) Calculate the amount due if John borrowed a sum of $3200 at 10% simple interest for 3 years.

(3) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.

(4) Calculate the amount due if Michael borrowed a sum of $3300 at 4% simple interest for 4 years.

(5) How much loan did Susan borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6497.5 to clear it?

(6) In how much time a principal of $3050 will amount to $3233 at a simple interest of 3% per annum?

(7) In how much time a principal of $3200 will amount to $3840 at a simple interest of 5% per annum?

(8) Calculate the amount due if Sarah borrowed a sum of $3850 at 3% simple interest for 3 years.

(9) Calculate the amount due if Susan borrowed a sum of $3650 at 4% simple interest for 3 years.

(10) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $10860 to clear the loan, then find the time period of the loan.


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