Simple Interest
MCQs Math


Question:     What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 5% simple interest?


Correct Answer  $3795

Solution And Explanation

Solution

Given,

Principal (P) = $3450

Rate of Simple Interest (SI) = 5%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3450 × 5% × 2

= $3450 ×5/100 × 2

= 3450 × 5 × 2/100

= 17250 × 2/100

= 34500/100

= $345

Thus, Simple Interest = $345

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 = $3450 + $345

= $3795

Thus, Amount to be paid = $3795 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 = $3450

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 2 years

Thus, Amount (A)

= $3450 + ($3450 × 5% × 2)

= $3450 + ($3450 ×5/100 × 2)

= $3450 + (3450 × 5 × 2/100)

= $3450 + (17250 × 2/100)

= $3450 + (34500/100)

= $3450 + $345 = $3795

Thus, Amount (A) to be paid = $3795 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $3450, the simple interest in 1 year

= 5/100 × 3450

= 5 × 3450/100

= 17250/100 = $172.5

Thus, simple interest for 1 year = $172.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $172.5 × 2 = $345

Thus, Simple Interest (SI) = $345

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $345

= $3795

Thus, Amount to be paid = $3795 Answer


Similar Questions

(1) Find the amount to be paid if William borrowed a sum of $5500 at 10% simple interest for 7 years.

(2) What amount does James have to pay after 5 years if he takes a loan of $3000 at 5% simple interest?

(3) Michael had to pay $3597 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(4) Matthew had to pay $4578 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(5) Find the amount to be paid if Susan borrowed a sum of $5650 at 2% simple interest for 8 years.

(6) What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 4% simple interest?

(7) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 2% simple interest?

(8) Charles took a loan of $5800 at the rate of 9% simple interest per annum. If he paid an amount of $8932 to clear the loan, then find the time period of the loan.

(9) If Betty paid $4760 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(10) Find the amount to be paid if Thomas borrowed a sum of $5800 at 7% simple interest for 8 years.


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