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) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 4% simple interest?

(2) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 9% simple interest?

(3) How much loan did Mark borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7040 to clear it?

(4) If Andrew paid $5760 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(5) What amount does James have to pay after 5 years if he takes a loan of $3000 at 10% simple interest?

(6) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $9943 to clear the loan, then find the time period of the loan.

(7) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $11524 to clear the loan, then find the time period of the loan.

(8) If Nancy paid $4648 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) In how much time a principal of $3200 will amount to $3840 at a simple interest of 4% per annum?

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


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