Simple Interest
MCQs Math


Question:     What amount does James have to pay after 6 years if he takes a loan of $3000 at 9% simple interest?


Correct Answer  $4620

Solution And Explanation

Solution

Given,

Principal (P) = $3000

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) = $3000 × 9% × 6

= $3000 ×9/100 × 6

= 3000 × 9 × 6/100

= 27000 × 6/100

= 162000/100

= $1620

Thus, Simple Interest = $1620

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 = $3000 + $1620

= $4620

Thus, Amount to be paid = $4620 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 = $3000

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3000 + ($3000 × 9% × 6)

= $3000 + ($3000 ×9/100 × 6)

= $3000 + (3000 × 9 × 6/100)

= $3000 + (27000 × 6/100)

= $3000 + (162000/100)

= $3000 + $1620 = $4620

Thus, Amount (A) to be paid = $4620 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 $3000, the simple interest in 1 year

= 9/100 × 3000

= 9 × 3000/100

= 27000/100 = $270

Thus, simple interest for 1 year = $270

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $270 × 6 = $1620

Thus, Simple Interest (SI) = $1620

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3000 + $1620

= $4620

Thus, Amount to be paid = $4620 Answer


Similar Questions

(1) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $11222 to clear the loan, then find the time period of the loan.

(2) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 4% simple interest?

(3) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 5% simple interest.

(4) If Jennifer paid $3900 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(5) Calculate the amount due if Sarah borrowed a sum of $3850 at 5% simple interest for 3 years.

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

(7) Calculate the amount due if William borrowed a sum of $3500 at 7% simple interest for 4 years.

(8) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 6% simple interest?

(9) Calculate the amount due if Barbara borrowed a sum of $3550 at 6% simple interest for 4 years.

(10) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $8428 to clear the loan, then find the time period of the loan.


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