Simple Interest
MCQs Math


Question:     Calculate the amount due if Susan borrowed a sum of $3650 at 8% simple interest for 3 years.


Correct Answer  $4526

Solution And Explanation

Solution

Given,

Principal (P) = $3650

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) = $3650 × 8% × 3

= $3650 ×8/100 × 3

= 3650 × 8 × 3/100

= 29200 × 3/100

= 87600/100

= $876

Thus, Simple Interest = $876

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 = $3650 + $876

= $4526

Thus, Amount to be paid = $4526 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 = $3650

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 3 years

Thus, Amount (A)

= $3650 + ($3650 × 8% × 3)

= $3650 + ($3650 ×8/100 × 3)

= $3650 + (3650 × 8 × 3/100)

= $3650 + (29200 × 3/100)

= $3650 + (87600/100)

= $3650 + $876 = $4526

Thus, Amount (A) to be paid = $4526 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 $3650, the simple interest in 1 year

= 8/100 × 3650

= 8 × 3650/100

= 29200/100 = $292

Thus, simple interest for 1 year = $292

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $292 × 3 = $876

Thus, Simple Interest (SI) = $876

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3650 + $876

= $4526

Thus, Amount to be paid = $4526 Answer


Similar Questions

(1) If John paid $3456 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(2) How much loan did Andrew borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7480 to clear it?

(3) Calculate the amount due if Charles borrowed a sum of $3900 at 4% simple interest for 3 years.

(4) How much loan did Susan borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6215 to clear it?

(5) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $10860 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 7% simple interest.

(7) What amount does David have to pay after 5 years if he takes a loan of $3400 at 6% simple interest?

(8) David had to pay $3910 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 2% simple interest?

(10) Matthew took a loan of $6400 at the rate of 10% simple interest per annum. If he paid an amount of $11520 to clear the loan, then find the time period of the loan.


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