Simple Interest
MCQs Math


Question:     What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 9% simple interest?


Correct Answer  $5621

Solution And Explanation

Solution

Given,

Principal (P) = $3650

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3650 × 9% × 6

= $3650 ×9/100 × 6

= 3650 × 9 × 6/100

= 32850 × 6/100

= 197100/100

= $1971

Thus, Simple Interest = $1971

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 = $3650 + $1971

= $5621

Thus, Amount to be paid = $5621 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 = $3650

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3650 + ($3650 × 9% × 6)

= $3650 + ($3650 ×9/100 × 6)

= $3650 + (3650 × 9 × 6/100)

= $3650 + (32850 × 6/100)

= $3650 + (197100/100)

= $3650 + $1971 = $5621

Thus, Amount (A) to be paid = $5621 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3650, the simple interest in 1 year

= 9/100 × 3650

= 9 × 3650/100

= 32850/100 = $328.5

Thus, simple interest for 1 year = $328.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $328.5 × 6 = $1971

Thus, Simple Interest (SI) = $1971

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3650 + $1971

= $5621

Thus, Amount to be paid = $5621 Answer


Similar Questions

(1) Richard had to pay $3816 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(2) Find the amount to be paid if Joseph borrowed a sum of $5700 at 9% simple interest for 8 years.

(3) Calculate the amount due if John borrowed a sum of $3200 at 6% simple interest for 3 years.

(4) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $7360 to clear the loan, then find the time period of the loan.

(5) Patricia took a loan of $4300 at the rate of 6% simple interest per annum. If he paid an amount of $6364 to clear the loan, then find the time period of the loan.

(6) How much loan did John borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5720 to clear it?

(7) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $9804 to clear the loan, then find the time period of the loan.

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

(9) Joseph took a loan of $5400 at the rate of 6% simple interest per annum. If he paid an amount of $7668 to clear the loan, then find the time period of the loan.

(10) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $5440 to clear the loan, then find the time period of the loan.


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