Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 9% simple interest?


Correct Answer  $5467

Solution And Explanation

Solution

Given,

Principal (P) = $3550

Rate of Simple Interest (SI) = 9%

Time (t) = 6 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% × 6

= $3550 ×9/100 × 6

= 3550 × 9 × 6/100

= 31950 × 6/100

= 191700/100

= $1917

Thus, Simple Interest = $1917

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 + $1917

= $5467

Thus, Amount to be paid = $5467 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) = 6 years

Thus, Amount (A)

= $3550 + ($3550 × 9% × 6)

= $3550 + ($3550 ×9/100 × 6)

= $3550 + (3550 × 9 × 6/100)

= $3550 + (31950 × 6/100)

= $3550 + (191700/100)

= $3550 + $1917 = $5467

Thus, Amount (A) to be paid = $5467 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 6 years

= Simple interest for 1 year × 6

= $319.5 × 6 = $1917

Thus, Simple Interest (SI) = $1917

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $1917

= $5467

Thus, Amount to be paid = $5467 Answer


Similar Questions

(1) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 7% simple interest?

(2) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 8% simple interest?

(3) Find the amount to be paid if Barbara borrowed a sum of $5550 at 7% simple interest for 7 years.

(4) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.

(5) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 9% simple interest.

(6) Mary had to pay $3233 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(7) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 2% simple interest for 8 years.

(8) How much loan did Paul borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8375 to clear it?

(9) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 8% simple interest?

(10) Sandra took a loan of $6900 at the rate of 6% simple interest per annum. If he paid an amount of $10626 to clear the loan, then find the time period of the loan.


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