Simple Interest
MCQs Math


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


Correct Answer  $4543

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $3850 × 3% × 6

= $3850 ×3/100 × 6

= 3850 × 3 × 6/100

= 11550 × 6/100

= 69300/100

= $693

Thus, Simple Interest = $693

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 = $3850 + $693

= $4543

Thus, Amount to be paid = $4543 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 = $3850

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3850 + ($3850 × 3% × 6)

= $3850 + ($3850 ×3/100 × 6)

= $3850 + (3850 × 3 × 6/100)

= $3850 + (11550 × 6/100)

= $3850 + (69300/100)

= $3850 + $693 = $4543

Thus, Amount (A) to be paid = $4543 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3850, the simple interest in 1 year

= 3/100 × 3850

= 3 × 3850/100

= 11550/100 = $115.5

Thus, simple interest for 1 year = $115.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $115.5 × 6 = $693

Thus, Simple Interest (SI) = $693

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $693

= $4543

Thus, Amount to be paid = $4543 Answer


Similar Questions

(1) Margaret took a loan of $6700 at the rate of 6% simple interest per annum. If he paid an amount of $10318 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Anthony borrowed a sum of $3650 at a 8% simple interest?

(3) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 5% simple interest?

(4) What amount does James have to pay after 6 years if he takes a loan of $3000 at 10% simple interest?

(5) If Thomas paid $4560 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(6) Barbara took a loan of $5100 at the rate of 7% simple interest per annum. If he paid an amount of $8313 to clear the loan, then find the time period of the loan.

(7) What amount does William have to pay after 6 years if he takes a loan of $3500 at 8% simple interest?

(8) In how much time a principal of $3150 will amount to $3276 at a simple interest of 2% per annum?

(9) If Elizabeth borrowed $3450 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(10) Calculate the amount due if Patricia borrowed a sum of $3150 at 3% simple interest for 4 years.


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