Simple Interest
MCQs Math


Question:     Find the amount to be paid if Karen borrowed a sum of $5950 at 3% simple interest for 8 years.


Correct Answer  $7378

Solution And Explanation

Solution

Given,

Principal (P) = $5950

Rate of Simple Interest (SI) = 3%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5950 × 3% × 8

= $5950 ×3/100 × 8

= 5950 × 3 × 8/100

= 17850 × 8/100

= 142800/100

= $1428

Thus, Simple Interest = $1428

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 = $5950 + $1428

= $7378

Thus, Amount to be paid = $7378 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 = $5950

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $5950 + ($5950 × 3% × 8)

= $5950 + ($5950 ×3/100 × 8)

= $5950 + (5950 × 3 × 8/100)

= $5950 + (17850 × 8/100)

= $5950 + (142800/100)

= $5950 + $1428 = $7378

Thus, Amount (A) to be paid = $7378 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $5950, the simple interest in 1 year

= 3/100 × 5950

= 3 × 5950/100

= 17850/100 = $178.5

Thus, simple interest for 1 year = $178.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $178.5 × 8 = $1428

Thus, Simple Interest (SI) = $1428

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $1428

= $7378

Thus, Amount to be paid = $7378 Answer


Similar Questions

(1) How much loan did Sarah borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6435 to clear it?

(2) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $13600 to clear the loan, then find the time period of the loan.

(3) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 6% simple interest?

(4) Calculate the amount due if John borrowed a sum of $3200 at 10% simple interest for 4 years.

(5) Find the amount to be paid if Karen borrowed a sum of $5950 at 4% simple interest for 7 years.

(6) Find the amount to be paid if Barbara borrowed a sum of $5550 at 7% simple interest for 7 years.

(7) If James borrowed $3000 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(8) Calculate the amount due if Michael borrowed a sum of $3300 at 6% simple interest for 4 years.

(9) If Karen paid $4582 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Calculate the amount due if Barbara borrowed a sum of $3550 at 4% simple interest for 3 years.


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