Simple Interest
MCQs Math


Question:     Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 2% simple interest.


Correct Answer  $7200

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 2%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $6000 × 2% × 10

= $6000 ×2/100 × 10

= 6000 × 2 × 10/100

= 12000 × 10/100

= 120000/100

= $1200

Thus, Simple Interest = $1200

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 = $6000 + $1200

= $7200

Thus, Amount to be paid = $7200 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 = $6000

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 10 years

Thus, Amount (A)

= $6000 + ($6000 × 2% × 10)

= $6000 + ($6000 ×2/100 × 10)

= $6000 + (6000 × 2 × 10/100)

= $6000 + (12000 × 10/100)

= $6000 + (120000/100)

= $6000 + $1200 = $7200

Thus, Amount (A) to be paid = $7200 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = 2/100

∴ For $6000, the simple interest in 1 year

= 2/100 × 6000

= 2 × 6000/100

= 12000/100 = $120

Thus, simple interest for 1 year = $120

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $120 × 10 = $1200

Thus, Simple Interest (SI) = $1200

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $1200

= $7200

Thus, Amount to be paid = $7200 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 5% simple interest.

(2) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 5% simple interest?

(3) What amount does Christopher have to pay after 5 years if he takes a loan of $4000 at 9% simple interest?

(4) Jennifer had to pay $3542.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(5) Susan took a loan of $5300 at the rate of 6% simple interest per annum. If he paid an amount of $7208 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if William borrowed a sum of $5500 at 4% simple interest for 8 years.

(7) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 9% simple interest.

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

(9) Sandra took a loan of $6900 at the rate of 6% simple interest per annum. If he paid an amount of $10212 to clear the loan, then find the time period of the loan.

(10) Jennifer had to pay $3737.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.


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