Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 9% simple interest?


Correct Answer  $5147.5

Solution And Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 9%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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 × 9% × 5

= $3550 ×9/100 × 5

= 3550 × 9 × 5/100

= 31950 × 5/100

= 159750/100

= $1597.5

Thus, Simple Interest = $1597.5

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 + $1597.5

= $5147.5

Thus, Amount to be paid = $5147.5 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) = 9%

And, Time (t) = 5 years

Thus, Amount (A)

= $3550 + ($3550 × 9% × 5)

= $3550 + ($3550 ×9/100 × 5)

= $3550 + (3550 × 9 × 5/100)

= $3550 + (31950 × 5/100)

= $3550 + (159750/100)

= $3550 + $1597.5 = $5147.5

Thus, Amount (A) to be paid = $5147.5 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3550, the simple interest in 1 year

= 9/100 × 3550

= 9 × 3550/100

= 31950/100 = $319.5

Thus, simple interest for 1 year = $319.5

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $319.5 × 5 = $1597.5

Thus, Simple Interest (SI) = $1597.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $1597.5

= $5147.5

Thus, Amount to be paid = $5147.5 Answer


Similar Questions

(1) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 4% simple interest for 3 years.

(2) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 8% simple interest?

(3) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 6% simple interest?

(4) Betty took a loan of $6500 at the rate of 9% simple interest per annum. If he paid an amount of $10595 to clear the loan, then find the time period of the loan.

(5) Find the amount to be paid if James borrowed a sum of $5000 at 5% simple interest for 7 years.

(6) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11160 to clear the loan, then find the time period of the loan.

(7) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 10% simple interest?

(8) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $9768 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 9% simple interest.

(10) Mark took a loan of $6800 at the rate of 6% simple interest per annum. If he paid an amount of $9656 to clear the loan, then find the time period of the loan.


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