Simple Interest
MCQs Math


Question:     What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 8% simple interest?


Correct Answer  $5624

Solution And Explanation

Solution

Given,

Principal (P) = $3800

Rate of Simple Interest (SI) = 8%

Time (t) = 6 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) = $3800 × 8% × 6

= $3800 ×8/100 × 6

= 3800 × 8 × 6/100

= 30400 × 6/100

= 182400/100

= $1824

Thus, Simple Interest = $1824

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 = $3800 + $1824

= $5624

Thus, Amount to be paid = $5624 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 = $3800

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3800 + ($3800 × 8% × 6)

= $3800 + ($3800 ×8/100 × 6)

= $3800 + (3800 × 8 × 6/100)

= $3800 + (30400 × 6/100)

= $3800 + (182400/100)

= $3800 + $1824 = $5624

Thus, Amount (A) to be paid = $5624 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 $3800, the simple interest in 1 year

= 8/100 × 3800

= 8 × 3800/100

= 30400/100 = $304

Thus, simple interest for 1 year = $304

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $304 × 6 = $1824

Thus, Simple Interest (SI) = $1824

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $1824

= $5624

Thus, Amount to be paid = $5624 Answer


Similar Questions

(1) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $11946 to clear the loan, then find the time period of the loan.

(2) Nancy took a loan of $6300 at the rate of 7% simple interest per annum. If he paid an amount of $10710 to clear the loan, then find the time period of the loan.

(3) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 9% simple interest for 8 years.

(4) Calculate the amount due if Christopher borrowed a sum of $4000 at 7% simple interest for 3 years.

(5) How much loan did Matthew borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7750 to clear it?

(6) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 7% simple interest.

(7) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 8% simple interest.

(8) In how much time a principal of $3150 will amount to $3622.5 at a simple interest of 5% per annum?

(9) Find the amount to be paid if Michael borrowed a sum of $5300 at 3% simple interest for 7 years.

(10) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 9% simple interest?


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