Simple Interest
MCQs Math


Question:     Find the amount to be paid if Christopher borrowed a sum of $6000 at 2% simple interest for 7 years.


Correct Answer  $6840

Solution And Explanation

Solution

Given,

Principal (P) = $6000

Rate of Simple Interest (SI) = 2%

Time (t) = 7 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% × 7

= $6000 ×2/100 × 7

= 6000 × 2 × 7/100

= 12000 × 7/100

= 84000/100

= $840

Thus, Simple Interest = $840

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 + $840

= $6840

Thus, Amount to be paid = $6840 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) = 7 years

Thus, Amount (A)

= $6000 + ($6000 × 2% × 7)

= $6000 + ($6000 ×2/100 × 7)

= $6000 + (6000 × 2 × 7/100)

= $6000 + (12000 × 7/100)

= $6000 + (84000/100)

= $6000 + $840 = $6840

Thus, Amount (A) to be paid = $6840 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 7 years

= Simple interest for 1 year × 7

= $120 × 7 = $840

Thus, Simple Interest (SI) = $840

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $6000 + $840

= $6840

Thus, Amount to be paid = $6840 Answer


Similar Questions

(1) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 10% simple interest?

(2) Calculate the amount due if Charles borrowed a sum of $3900 at 7% simple interest for 3 years.

(3) Nancy had to pay $4523.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(4) How much loan did Richard borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7000 to clear it?

(5) How much loan did Andrew borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8160 to clear it?

(6) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 2% simple interest?

(7) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $11946 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if James borrowed a sum of $5000 at 7% simple interest for 8 years.

(9) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $8624 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 7 years.


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