Simple Interest
MCQs Math


Question:     What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 10% simple interest?


Correct Answer  $5325

Solution And Explanation

Solution

Given,

Principal (P) = $3550

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) = $3550 × 10% × 5

= $3550 ×10/100 × 5

= 3550 × 10 × 5/100

= 35500 × 5/100

= 177500/100

= $1775

Thus, Simple Interest = $1775

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 + $1775

= $5325

Thus, Amount to be paid = $5325 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) = 10%

And, Time (t) = 5 years

Thus, Amount (A)

= $3550 + ($3550 × 10% × 5)

= $3550 + ($3550 ×10/100 × 5)

= $3550 + (3550 × 10 × 5/100)

= $3550 + (35500 × 5/100)

= $3550 + (177500/100)

= $3550 + $1775 = $5325

Thus, Amount (A) to be paid = $5325 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 $3550, the simple interest in 1 year

= 10/100 × 3550

= 10 × 3550/100

= 35500/100 = $355

Thus, simple interest for 1 year = $355

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $355 × 5 = $1775

Thus, Simple Interest (SI) = $1775

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3550 + $1775

= $5325

Thus, Amount to be paid = $5325 Answer


Similar Questions

(1) In how much time a principal of $3200 will amount to $3712 at a simple interest of 4% per annum?

(2) If Andrew paid $5184 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(3) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 9% simple interest?

(4) Mark had to pay $4664 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 4% simple interest.

(6) Find the amount to be paid if James borrowed a sum of $5000 at 4% simple interest for 8 years.

(7) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $9500 to clear the loan, then find the time period of the loan.

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

(9) Linda had to pay $3651.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $7854 to clear the loan, then find the time period of the loan.


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