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) Find the amount to be paid if Karen borrowed a sum of $5950 at 9% simple interest for 8 years.

(2) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 3% simple interest for 7 years.

(3) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $9828 to clear the loan, then find the time period of the loan.

(4) Charles took a loan of $5800 at the rate of 6% simple interest per annum. If he paid an amount of $9280 to clear the loan, then find the time period of the loan.

(5) Betty took a loan of $6500 at the rate of 8% simple interest per annum. If he paid an amount of $10660 to clear the loan, then find the time period of the loan.

(6) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 6% simple interest?

(7) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 9% simple interest.

(8) If Anthony paid $5160 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) Matthew took a loan of $6400 at the rate of 10% simple interest per annum. If he paid an amount of $12800 to clear the loan, then find the time period of the loan.

(10) In how much time a principal of $3150 will amount to $3339 at a simple interest of 2% per annum?


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