Simple Interest
MCQs Math


Question:     What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 7% simple interest?


Correct Answer  $5467

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 7%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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 × 7% × 6

= $3850 ×7/100 × 6

= 3850 × 7 × 6/100

= 26950 × 6/100

= 161700/100

= $1617

Thus, Simple Interest = $1617

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 + $1617

= $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 = $3850

Rate of Simple Interest (SI) or (R) = 7%

And, Time (t) = 6 years

Thus, Amount (A)

= $3850 + ($3850 × 7% × 6)

= $3850 + ($3850 ×7/100 × 6)

= $3850 + (3850 × 7 × 6/100)

= $3850 + (26950 × 6/100)

= $3850 + (161700/100)

= $3850 + $1617 = $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 = 7%

This, means, $7 per $100 per year

∵ For $100, the simple interest for 1 year = $7

∴ For $1, the simple interest for 1 year = 7/100

∴ For $3850, the simple interest in 1 year

= 7/100 × 3850

= 7 × 3850/100

= 26950/100 = $269.5

Thus, simple interest for 1 year = $269.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $269.5 × 6 = $1617

Thus, Simple Interest (SI) = $1617

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $1617

= $5467

Thus, Amount to be paid = $5467 Answer


Similar Questions

(1) Calculate the amount due if Richard borrowed a sum of $3600 at 5% simple interest for 4 years.

(2) Mark took a loan of $6800 at the rate of 9% simple interest per annum. If he paid an amount of $10472 to clear the loan, then find the time period of the loan.

(3) Christopher had to pay $4240 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(4) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $11041 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 7% simple interest.

(6) How much loan did Jessica borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6612.5 to clear it?

(7) How much loan did Joshua borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8625 to clear it?

(8) Calculate the amount due if William borrowed a sum of $3500 at 5% simple interest for 3 years.

(9) Calculate the amount due if James borrowed a sum of $3000 at 3% simple interest for 4 years.

(10) How much loan did Daniel borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6710 to clear it?


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