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) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $8150 to clear the loan, then find the time period of the loan.

(2) If Susan paid $4380 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) Lisa had to pay $4293 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(4) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 8% simple interest.

(5) Calculate the amount due if Michael borrowed a sum of $3300 at 9% simple interest for 3 years.

(6) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 8 years.

(7) Calculate the amount due if Linda borrowed a sum of $3350 at 5% simple interest for 4 years.

(8) How much loan did Patricia borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6180 to clear it?

(9) If James paid $3480 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Betty took a loan of $6500 at the rate of 6% simple interest per annum. If he paid an amount of $9230 to clear the loan, then find the time period of the loan.


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