Simple Interest
MCQs Math


Question:     Calculate the amount due if Karen borrowed a sum of $3950 at 8% simple interest for 3 years.


Correct Answer  $4898

Solution And Explanation

Solution

Given,

Principal (P) = $3950

Rate of Simple Interest (SI) = 8%

Time (t) = 3 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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 × 8% × 3

= $3950 ×8/100 × 3

= 3950 × 8 × 3/100

= 31600 × 3/100

= 94800/100

= $948

Thus, Simple Interest = $948

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 + $948

= $4898

Thus, Amount to be paid = $4898 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) = 8%

And, Time (t) = 3 years

Thus, Amount (A)

= $3950 + ($3950 × 8% × 3)

= $3950 + ($3950 ×8/100 × 3)

= $3950 + (3950 × 8 × 3/100)

= $3950 + (31600 × 3/100)

= $3950 + (94800/100)

= $3950 + $948 = $4898

Thus, Amount (A) to be paid = $4898 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $3950, the simple interest in 1 year

= 8/100 × 3950

= 8 × 3950/100

= 31600/100 = $316

Thus, simple interest for 1 year = $316

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $316 × 3 = $948

Thus, Simple Interest (SI) = $948

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3950 + $948

= $4898

Thus, Amount to be paid = $4898 Answer


Similar Questions

(1) Calculate the amount due if Jennifer borrowed a sum of $3250 at 9% simple interest for 4 years.

(2) Mark had to pay $4796 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(3) What amount will be due after 2 years if William borrowed a sum of $3250 at a 10% simple interest?

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 6% simple interest?

(5) Robert took a loan of $4200 at the rate of 7% simple interest per annum. If he paid an amount of $5964 to clear the loan, then find the time period of the loan.

(6) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 5% simple interest?

(7) How much loan did Ryan borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8690 to clear it?

(8) What amount does James have to pay after 6 years if he takes a loan of $3000 at 9% simple interest?

(9) If Charles borrowed $3900 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(10) Find the amount to be paid if Karen borrowed a sum of $5950 at 7% simple interest for 7 years.


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