Simple Interest
MCQs Math


Question:     What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 9% simple interest?


Correct Answer  $4851

Solution And Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3150 × 9% × 6

= $3150 ×9/100 × 6

= 3150 × 9 × 6/100

= 28350 × 6/100

= 170100/100

= $1701

Thus, Simple Interest = $1701

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 = $3150 + $1701

= $4851

Thus, Amount to be paid = $4851 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 = $3150

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3150 + ($3150 × 9% × 6)

= $3150 + ($3150 ×9/100 × 6)

= $3150 + (3150 × 9 × 6/100)

= $3150 + (28350 × 6/100)

= $3150 + (170100/100)

= $3150 + $1701 = $4851

Thus, Amount (A) to be paid = $4851 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3150, the simple interest in 1 year

= 9/100 × 3150

= 9 × 3150/100

= 28350/100 = $283.5

Thus, simple interest for 1 year = $283.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $283.5 × 6 = $1701

Thus, Simple Interest (SI) = $1701

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $1701

= $4851

Thus, Amount to be paid = $4851 Answer


Similar Questions

(1) If Patricia paid $3780 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(2) Find the amount to be paid if Christopher borrowed a sum of $6000 at 7% simple interest for 7 years.

(3) How much loan did Patricia borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5665 to clear it?

(4) Calculate the amount due if John borrowed a sum of $3200 at 7% simple interest for 3 years.

(5) Mary had to pay $3507.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(6) Donald took a loan of $7000 at the rate of 7% simple interest per annum. If he paid an amount of $10430 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 6% simple interest.

(8) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6560 to clear the loan, then find the time period of the loan.

(9) John took a loan of $4400 at the rate of 8% simple interest per annum. If he paid an amount of $7920 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due if Jennifer borrowed a sum of $3250 at 6% simple interest for 4 years.


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