Simple Interest
MCQs Math


Question:     What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 7% simple interest?


Correct Answer  $5609

Solution And Explanation

Solution

Given,

Principal (P) = $3950

Rate of Simple Interest (SI) = 7%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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 × 7% × 6

= $3950 ×7/100 × 6

= 3950 × 7 × 6/100

= 27650 × 6/100

= 165900/100

= $1659

Thus, Simple Interest = $1659

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 + $1659

= $5609

Thus, Amount to be paid = $5609 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) = 7%

And, Time (t) = 6 years

Thus, Amount (A)

= $3950 + ($3950 × 7% × 6)

= $3950 + ($3950 ×7/100 × 6)

= $3950 + (3950 × 7 × 6/100)

= $3950 + (27650 × 6/100)

= $3950 + (165900/100)

= $3950 + $1659 = $5609

Thus, Amount (A) to be paid = $5609 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 7%

This, means, $7 per $100 per year

∵ For $100, the simple interest for 1 year = $7

∴ For $1, the simple interest for 1 year = 7/100

∴ For $3950, the simple interest in 1 year

= 7/100 × 3950

= 7 × 3950/100

= 27650/100 = $276.5

Thus, simple interest for 1 year = $276.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $276.5 × 6 = $1659

Thus, Simple Interest (SI) = $1659

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3950 + $1659

= $5609

Thus, Amount to be paid = $5609 Answer


Similar Questions

(1) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 4% simple interest?

(2) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 2% simple interest.

(3) Calculate the amount due if Michael borrowed a sum of $3300 at 10% simple interest for 3 years.

(4) Charles had to pay $4485 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(5) Calculate the amount due after 10 years if Sarah borrowed a sum of $5850 at a rate of 6% simple interest.

(6) John had to pay $3680 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(7) Calculate the amount due if David borrowed a sum of $3400 at 3% simple interest for 3 years.

(8) Susan took a loan of $5300 at the rate of 6% simple interest per annum. If he paid an amount of $8162 to clear the loan, then find the time period of the loan.

(9) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $7668 to clear the loan, then find the time period of the loan.

(10) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 9% simple interest?


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