Simple Interest
MCQs Math


Question:     What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 5% simple interest?


Correct Answer  $4680

Solution And Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 5%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3600 × 5% × 6

= $3600 ×5/100 × 6

= 3600 × 5 × 6/100

= 18000 × 6/100

= 108000/100

= $1080

Thus, Simple Interest = $1080

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 = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 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 = $3600

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 6 years

Thus, Amount (A)

= $3600 + ($3600 × 5% × 6)

= $3600 + ($3600 ×5/100 × 6)

= $3600 + (3600 × 5 × 6/100)

= $3600 + (18000 × 6/100)

= $3600 + (108000/100)

= $3600 + $1080 = $4680

Thus, Amount (A) to be paid = $4680 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $3600, the simple interest in 1 year

= 5/100 × 3600

= 5 × 3600/100

= 18000/100 = $180

Thus, simple interest for 1 year = $180

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $180 × 6 = $1080

Thus, Simple Interest (SI) = $1080

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $1080

= $4680

Thus, Amount to be paid = $4680 Answer


Similar Questions

(1) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 2% simple interest?

(2) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $10164 to clear the loan, then find the time period of the loan.

(3) Find the amount to be paid if Patricia borrowed a sum of $5150 at 7% simple interest for 7 years.

(4) Karen took a loan of $5900 at the rate of 8% simple interest per annum. If he paid an amount of $10148 to clear the loan, then find the time period of the loan.

(5) Find the amount to be paid if William borrowed a sum of $5500 at 3% simple interest for 7 years.

(6) Nancy took a loan of $6300 at the rate of 7% simple interest per annum. If he paid an amount of $9387 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due if William borrowed a sum of $3500 at 8% simple interest for 4 years.

(8) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 8% simple interest?

(9) What amount will be due after 2 years if John borrowed a sum of $3100 at a 10% simple interest?

(10) What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 9% simple interest?


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