Simple Interest
MCQs Math


Question:     Find the amount to be paid if Jessica borrowed a sum of $5750 at 3% simple interest for 8 years.


Correct Answer  $7130

Solution And Explanation

Solution

Given,

Principal (P) = $5750

Rate of Simple Interest (SI) = 3%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5750 × 3% × 8

= $5750 ×3/100 × 8

= 5750 × 3 × 8/100

= 17250 × 8/100

= 138000/100

= $1380

Thus, Simple Interest = $1380

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 = $5750 + $1380

= $7130

Thus, Amount to be paid = $7130 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 = $5750

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $5750 + ($5750 × 3% × 8)

= $5750 + ($5750 ×3/100 × 8)

= $5750 + (5750 × 3 × 8/100)

= $5750 + (17250 × 8/100)

= $5750 + (138000/100)

= $5750 + $1380 = $7130

Thus, Amount (A) to be paid = $7130 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $5750, the simple interest in 1 year

= 3/100 × 5750

= 3 × 5750/100

= 17250/100 = $172.5

Thus, simple interest for 1 year = $172.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $172.5 × 8 = $1380

Thus, Simple Interest (SI) = $1380

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5750 + $1380

= $7130

Thus, Amount to be paid = $7130 Answer


Similar Questions

(1) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $9690 to clear the loan, then find the time period of the loan.

(2) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $8436 to clear the loan, then find the time period of the loan.

(3) John had to pay $3584 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(4) Nancy took a loan of $6300 at the rate of 10% simple interest per annum. If he paid an amount of $10710 to clear the loan, then find the time period of the loan.

(5) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 9% simple interest?

(6) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $13800 to clear the loan, then find the time period of the loan.

(7) Find the amount to be paid if Richard borrowed a sum of $5600 at 7% simple interest for 8 years.

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

(9) Betty had to pay $4632.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(10) Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $11390 to clear the loan, then find the time period of the loan.


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