Simple Interest
MCQs Math


Question:     Find the amount to be paid if Joseph borrowed a sum of $5700 at 5% simple interest for 8 years.


Correct Answer  $7980

Solution And Explanation

Solution

Given,

Principal (P) = $5700

Rate of Simple Interest (SI) = 5%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $5700 × 5% × 8

= $5700 ×5/100 × 8

= 5700 × 5 × 8/100

= 28500 × 8/100

= 228000/100

= $2280

Thus, Simple Interest = $2280

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 = $5700 + $2280

= $7980

Thus, Amount to be paid = $7980 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 = $5700

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 8 years

Thus, Amount (A)

= $5700 + ($5700 × 5% × 8)

= $5700 + ($5700 ×5/100 × 8)

= $5700 + (5700 × 5 × 8/100)

= $5700 + (28500 × 8/100)

= $5700 + (228000/100)

= $5700 + $2280 = $7980

Thus, Amount (A) to be paid = $7980 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $5700, the simple interest in 1 year

= 5/100 × 5700

= 5 × 5700/100

= 28500/100 = $285

Thus, simple interest for 1 year = $285

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $285 × 8 = $2280

Thus, Simple Interest (SI) = $2280

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5700 + $2280

= $7980

Thus, Amount to be paid = $7980 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 6% simple interest.

(2) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 4% simple interest?

(3) Calculate the amount due if Richard borrowed a sum of $3600 at 6% simple interest for 3 years.

(4) If Lisa paid $4536 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(5) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $6256 to clear the loan, then find the time period of the loan.

(6) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 9% simple interest?

(7) If Robert paid $3720 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(8) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $13110 to clear the loan, then find the time period of the loan.

(9) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 10% simple interest?

(10) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 2% simple interest?


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