Simple Interest
MCQs Math


Question:     Calculate the amount due if Karen borrowed a sum of $3950 at 2% simple interest for 4 years.


Correct Answer  $4266

Solution And Explanation

Solution

Given,

Principal (P) = $3950

Rate of Simple Interest (SI) = 2%

Time (t) = 4 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) = $3950 × 2% × 4

= $3950 ×2/100 × 4

= 3950 × 2 × 4/100

= 7900 × 4/100

= 31600/100

= $316

Thus, Simple Interest = $316

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 = $3950 + $316

= $4266

Thus, Amount to be paid = $4266 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 = $3950

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 4 years

Thus, Amount (A)

= $3950 + ($3950 × 2% × 4)

= $3950 + ($3950 ×2/100 × 4)

= $3950 + (3950 × 2 × 4/100)

= $3950 + (7900 × 4/100)

= $3950 + (31600/100)

= $3950 + $316 = $4266

Thus, Amount (A) to be paid = $4266 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 $3950, the simple interest in 1 year

= 2/100 × 3950

= 2 × 3950/100

= 7900/100 = $79

Thus, simple interest for 1 year = $79

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $79 × 4 = $316

Thus, Simple Interest (SI) = $316

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3950 + $316

= $4266

Thus, Amount to be paid = $4266 Answer


Similar Questions

(1) Find the amount to be paid if Susan borrowed a sum of $5650 at 2% simple interest for 8 years.

(2) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 5% simple interest?

(3) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 5% simple interest?

(4) Richard took a loan of $5200 at the rate of 10% simple interest per annum. If he paid an amount of $8320 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 3% simple interest for 3 years.

(6) Find the amount to be paid if Susan borrowed a sum of $5650 at 4% simple interest for 8 years.

(7) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 4% simple interest for 7 years.

(8) Calculate the amount due if Patricia borrowed a sum of $3150 at 8% simple interest for 3 years.

(9) What amount does Elizabeth have to pay after 5 years if he takes a loan of $3450 at 3% simple interest?

(10) Susan took a loan of $5300 at the rate of 7% simple interest per annum. If he paid an amount of $9010 to clear the loan, then find the time period of the loan.


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