Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 8% simple interest.


Correct Answer  $9976

Solution And Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 8%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $5800 × 8% × 9

= $5800 ×8/100 × 9

= 5800 × 8 × 9/100

= 46400 × 9/100

= 417600/100

= $4176

Thus, Simple Interest = $4176

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 = $5800 + $4176

= $9976

Thus, Amount to be paid = $9976 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 = $5800

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 9 years

Thus, Amount (A)

= $5800 + ($5800 × 8% × 9)

= $5800 + ($5800 ×8/100 × 9)

= $5800 + (5800 × 8 × 9/100)

= $5800 + (46400 × 9/100)

= $5800 + (417600/100)

= $5800 + $4176 = $9976

Thus, Amount (A) to be paid = $9976 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $5800, the simple interest in 1 year

= 8/100 × 5800

= 8 × 5800/100

= 46400/100 = $464

Thus, simple interest for 1 year = $464

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $464 × 9 = $4176

Thus, Simple Interest (SI) = $4176

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $4176

= $9976

Thus, Amount to be paid = $9976 Answer


Similar Questions

(1) Betty took a loan of $6500 at the rate of 10% simple interest per annum. If he paid an amount of $10400 to clear the loan, then find the time period of the loan.

(2) Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $7956 to clear the loan, then find the time period of the loan.

(3) If Barbara paid $3976 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(4) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $8800 to clear the loan, then find the time period of the loan.

(5) How much loan did Joseph borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7125 to clear it?

(6) Nancy took a loan of $6300 at the rate of 10% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.

(7) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 2% simple interest?

(8) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $12000 to clear the loan, then find the time period of the loan.

(9) If Michael paid $3828 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Sandra took a loan of $6900 at the rate of 9% simple interest per annum. If he paid an amount of $12489 to clear the loan, then find the time period of the loan.


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