Simple Interest
MCQs Math


Question:     What amount does James have to pay after 6 years if he takes a loan of $3000 at 10% simple interest?


Correct Answer  $4800

Solution And Explanation

Solution

Given,

Principal (P) = $3000

Rate of Simple Interest (SI) = 10%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3000 × 10% × 6

= $3000 ×10/100 × 6

= 3000 × 10 × 6/100

= 30000 × 6/100

= 180000/100

= $1800

Thus, Simple Interest = $1800

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 = $3000 + $1800

= $4800

Thus, Amount to be paid = $4800 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 = $3000

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 6 years

Thus, Amount (A)

= $3000 + ($3000 × 10% × 6)

= $3000 + ($3000 ×10/100 × 6)

= $3000 + (3000 × 10 × 6/100)

= $3000 + (30000 × 6/100)

= $3000 + (180000/100)

= $3000 + $1800 = $4800

Thus, Amount (A) to be paid = $4800 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $3000, the simple interest in 1 year

= 10/100 × 3000

= 10 × 3000/100

= 30000/100 = $300

Thus, simple interest for 1 year = $300

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $300 × 6 = $1800

Thus, Simple Interest (SI) = $1800

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3000 + $1800

= $4800

Thus, Amount to be paid = $4800 Answer


Similar Questions

(1) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 8% simple interest?

(2) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 7% simple interest.

(3) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $5680 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 8 years.

(5) How much loan did Amanda borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8222.5 to clear it?

(6) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 2% simple interest for 7 years.

(7) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 5% simple interest.

(8) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 3% simple interest?

(9) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 7% simple interest.

(10) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 5% simple interest.


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