Simple Interest
MCQs Math


Question:     What amount does David have to pay after 5 years if he takes a loan of $3400 at 8% simple interest?


Correct Answer  $4760

Solution And Explanation

Solution

Given,

Principal (P) = $3400

Rate of Simple Interest (SI) = 8%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $3400 × 8% × 5

= $3400 ×8/100 × 5

= 3400 × 8 × 5/100

= 27200 × 5/100

= 136000/100

= $1360

Thus, Simple Interest = $1360

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 = $3400 + $1360

= $4760

Thus, Amount to be paid = $4760 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 = $3400

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 5 years

Thus, Amount (A)

= $3400 + ($3400 × 8% × 5)

= $3400 + ($3400 ×8/100 × 5)

= $3400 + (3400 × 8 × 5/100)

= $3400 + (27200 × 5/100)

= $3400 + (136000/100)

= $3400 + $1360 = $4760

Thus, Amount (A) to be paid = $4760 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $3400, the simple interest in 1 year

= 8/100 × 3400

= 8 × 3400/100

= 27200/100 = $272

Thus, simple interest for 1 year = $272

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $272 × 5 = $1360

Thus, Simple Interest (SI) = $1360

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3400 + $1360

= $4760

Thus, Amount to be paid = $4760 Answer


Similar Questions

(1) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 5% simple interest?

(2) Thomas took a loan of $5600 at the rate of 6% simple interest per annum. If he paid an amount of $7952 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due if Susan borrowed a sum of $3650 at 10% simple interest for 4 years.

(4) If Christopher borrowed $4000 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

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

(6) If Donna paid $5820 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(7) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 7% simple interest.

(8) Calculate the amount due if Mary borrowed a sum of $3050 at 7% simple interest for 3 years.

(9) Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.

(10) Joseph took a loan of $5400 at the rate of 8% simple interest per annum. If he paid an amount of $8856 to clear the loan, then find the time period of the loan.


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