Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 5% simple interest?


Correct Answer  $4615

Solution And Explanation

Solution

Given,

Principal (P) = $3550

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) = $3550 × 5% × 6

= $3550 ×5/100 × 6

= 3550 × 5 × 6/100

= 17750 × 6/100

= 106500/100

= $1065

Thus, Simple Interest = $1065

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 = $3550 + $1065

= $4615

Thus, Amount to be paid = $4615 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 = $3550

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3550 + ($3550 × 5% × 6)

= $3550 + ($3550 ×5/100 × 6)

= $3550 + (3550 × 5 × 6/100)

= $3550 + (17750 × 6/100)

= $3550 + (106500/100)

= $3550 + $1065 = $4615

Thus, Amount (A) to be paid = $4615 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 $3550, the simple interest in 1 year

= 5/100 × 3550

= 5 × 3550/100

= 17750/100 = $177.5

Thus, simple interest for 1 year = $177.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $177.5 × 6 = $1065

Thus, Simple Interest (SI) = $1065

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $1065

= $4615

Thus, Amount to be paid = $4615 Answer


Similar Questions

(1) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 8% simple interest.

(2) If Mary paid $3416 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(3) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $12400 to clear the loan, then find the time period of the loan.

(4) What amount will be due after 2 years if William borrowed a sum of $3250 at a 6% simple interest?

(5) Patricia took a loan of $4300 at the rate of 7% simple interest per annum. If he paid an amount of $6708 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if Michael borrowed a sum of $5300 at 4% simple interest for 7 years.

(7) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 9% simple interest?

(8) If James paid $3360 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 2% simple interest.

(10) Calculate the amount due if Karen borrowed a sum of $3950 at 2% simple interest for 4 years.


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