Simple Interest
MCQs Math


Question:     What amount does James have to pay after 5 years if he takes a loan of $3000 at 10% simple interest?


Correct Answer  $4500

Solution And Explanation

Solution

Given,

Principal (P) = $3000

Rate of Simple Interest (SI) = 10%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 5

= $3000 ×10/100 × 5

= 3000 × 10 × 5/100

= 30000 × 5/100

= 150000/100

= $1500

Thus, Simple Interest = $1500

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 + $1500

= $4500

Thus, Amount to be paid = $4500 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) = 10%

And, Time (t) = 5 years

Thus, Amount (A)

= $3000 + ($3000 × 10% × 5)

= $3000 + ($3000 ×10/100 × 5)

= $3000 + (3000 × 10 × 5/100)

= $3000 + (30000 × 5/100)

= $3000 + (150000/100)

= $3000 + $1500 = $4500

Thus, Amount (A) to be paid = $4500 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $3000, the simple interest in 1 year

= 10/100 × 3000

= 10 × 3000/100

= 30000/100 = $300

Thus, simple interest for 1 year = $300

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $300 × 5 = $1500

Thus, Simple Interest (SI) = $1500

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3000 + $1500

= $4500

Thus, Amount to be paid = $4500 Answer


Similar Questions

(1) If David borrowed $3400 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(2) Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $12060 to clear the loan, then find the time period of the loan.

(3) What amount does John have to pay after 5 years if he takes a loan of $3200 at 8% simple interest?

(4) Find the amount to be paid if William borrowed a sum of $5500 at 6% simple interest for 7 years.

(5) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $7912 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if Michael borrowed a sum of $5300 at 10% simple interest for 7 years.

(7) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $9856 to clear the loan, then find the time period of the loan.

(8) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $10921 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if William borrowed a sum of $3500 at 6% simple interest for 4 years.

(10) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $10758 to clear the loan, then find the time period of the loan.


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