Simple Interest
MCQs Math


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


Correct Answer  $5005

Solution And Explanation

Solution

Given,

Principal (P) = $3850

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

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

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

= $3850 ×6/100 × 5

= 3850 × 6 × 5/100

= 23100 × 5/100

= 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) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3850 + ($3850 × 6% × 5)

= $3850 + ($3850 ×6/100 × 5)

= $3850 + (3850 × 6 × 5/100)

= $3850 + (23100 × 5/100)

= $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 = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3850, the simple interest in 1 year

= 6/100 × 3850

= 6 × 3850/100

= 23100/100 = $231

Thus, simple interest for 1 year = $231

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $231 × 5 = $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) How much loan did Donald borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7475 to clear it?

(2) In how much time a principal of $3200 will amount to $3488 at a simple interest of 3% per annum?

(3) Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 7 years.

(4) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 7% simple interest.

(5) What amount does David have to pay after 6 years if he takes a loan of $3400 at 8% simple interest?

(6) Find the amount to be paid if Susan borrowed a sum of $5650 at 5% simple interest for 7 years.

(7) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 6% simple interest?

(8) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 10% simple interest.

(9) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $9880 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 9% simple interest.


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