Simple Interest
MCQs Math


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


Correct Answer  $4284

Solution And Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 6%

Time (t) = 6 years

Thus, Amount (A) = ?

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

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

= $3150 ×6/100 × 6

= 3150 × 6 × 6/100

= 18900 × 6/100

= 113400/100

= $1134

Thus, Simple Interest = $1134

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 + $1134

= $4284

Thus, Amount to be paid = $4284 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) = 6%

And, Time (t) = 6 years

Thus, Amount (A)

= $3150 + ($3150 × 6% × 6)

= $3150 + ($3150 ×6/100 × 6)

= $3150 + (3150 × 6 × 6/100)

= $3150 + (18900 × 6/100)

= $3150 + (113400/100)

= $3150 + $1134 = $4284

Thus, Amount (A) to be paid = $4284 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3150, the simple interest in 1 year

= 6/100 × 3150

= 6 × 3150/100

= 18900/100 = $189

Thus, simple interest for 1 year = $189

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $189 × 6 = $1134

Thus, Simple Interest (SI) = $1134

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $1134

= $4284

Thus, Amount to be paid = $4284 Answer


Similar Questions

(1) Find the amount to be paid if Richard borrowed a sum of $5600 at 5% simple interest for 7 years.

(2) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7488 to clear the loan, then find the time period of the loan.

(3) How much loan did Lisa borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7562.5 to clear it?

(4) Calculate the amount due if David borrowed a sum of $3400 at 5% simple interest for 4 years.

(5) Jennifer took a loan of $4500 at the rate of 7% simple interest per annum. If he paid an amount of $6390 to clear the loan, then find the time period of the loan.

(6) How much loan did Dorothy borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9062.5 to clear it?

(7) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 7% simple interest?

(8) If Nancy paid $4980 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) Find the amount to be paid if Barbara borrowed a sum of $5550 at 10% simple interest for 8 years.

(10) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $8378 to clear the loan, then find the time period of the loan.


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