Simple Interest
MCQs Math


Question:     What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 10% simple interest?


Correct Answer  $4725

Solution And Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 10%

Time (t) = 5 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) = $3150 × 10% × 5

= $3150 ×10/100 × 5

= 3150 × 10 × 5/100

= 31500 × 5/100

= 157500/100

= $1575

Thus, Simple Interest = $1575

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 + $1575

= $4725

Thus, Amount to be paid = $4725 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) = 10%

And, Time (t) = 5 years

Thus, Amount (A)

= $3150 + ($3150 × 10% × 5)

= $3150 + ($3150 ×10/100 × 5)

= $3150 + (3150 × 10 × 5/100)

= $3150 + (31500 × 5/100)

= $3150 + (157500/100)

= $3150 + $1575 = $4725

Thus, Amount (A) to be paid = $4725 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 $3150, the simple interest in 1 year

= 10/100 × 3150

= 10 × 3150/100

= 31500/100 = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $315 × 5 = $1575

Thus, Simple Interest (SI) = $1575

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $1575

= $4725

Thus, Amount to be paid = $4725 Answer


Similar Questions

(1) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Sarah borrowed a sum of $3850 at 8% simple interest for 3 years.

(3) Jennifer took a loan of $4500 at the rate of 9% simple interest per annum. If he paid an amount of $6930 to clear the loan, then find the time period of the loan.

(4) What amount does William have to pay after 5 years if he takes a loan of $3500 at 5% simple interest?

(5) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 7% simple interest?

(6) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $9943 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 3% simple interest.

(8) What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 4% simple interest?

(9) William took a loan of $5000 at the rate of 6% simple interest per annum. If he paid an amount of $7100 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if Linda borrowed a sum of $5350 at 8% simple interest for 7 years.


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