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) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $11247 to clear the loan, then find the time period of the loan.

(2) If Mark paid $4928 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(3) How much loan did Ashley borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7860 to clear it?

(4) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 7% simple interest.

(5) In how much time a principal of $3050 will amount to $3355 at a simple interest of 2% per annum?

(6) How much loan did George borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9125 to clear it?

(7) Barbara took a loan of $5100 at the rate of 10% simple interest per annum. If he paid an amount of $10200 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 2% simple interest.

(9) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9760 to clear the loan, then find the time period of the loan.

(10) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 2% simple interest?


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