Simple Interest
MCQs Math


Question:     What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 5% simple interest?


Correct Answer  $5005

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 5%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 6

= $3850 ×5/100 × 6

= 3850 × 5 × 6/100

= 19250 × 6/100

= 115500/100

= $1155

Thus, Simple Interest = $1155

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 + $1155

= $5005

Thus, Amount to be paid = $5005 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) = 5%

And, Time (t) = 6 years

Thus, Amount (A)

= $3850 + ($3850 × 5% × 6)

= $3850 + ($3850 ×5/100 × 6)

= $3850 + (3850 × 5 × 6/100)

= $3850 + (19250 × 6/100)

= $3850 + (115500/100)

= $3850 + $1155 = $5005

Thus, Amount (A) to be paid = $5005 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $3850, the simple interest in 1 year

= 5/100 × 3850

= 5 × 3850/100

= 19250/100 = $192.5

Thus, simple interest for 1 year = $192.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $192.5 × 6 = $1155

Thus, Simple Interest (SI) = $1155

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $1155

= $5005

Thus, Amount to be paid = $5005 Answer


Similar Questions

(1) Calculate the amount due if John borrowed a sum of $3200 at 7% simple interest for 3 years.

(2) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $11008 to clear the loan, then find the time period of the loan.

(3) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8312.5 to clear it?

(4) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $9512 to clear the loan, then find the time period of the loan.

(5) How much loan did Linda borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6420 to clear it?

(6) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 7% simple interest.

(7) Robert took a loan of $4200 at the rate of 10% simple interest per annum. If he paid an amount of $8400 to clear the loan, then find the time period of the loan.

(8) How much loan did Sarah borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7020 to clear it?

(9) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 7 years.

(10) How much loan did Patricia borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $5922.5 to clear it?


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