Simple Interest
MCQs Math


Question:     What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 6% simple interest?


Correct Answer  $4940

Solution And Explanation

Solution

Given,

Principal (P) = $3800

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3800 × 6% × 5

= $3800 ×6/100 × 5

= 3800 × 6 × 5/100

= 22800 × 5/100

= 114000/100

= $1140

Thus, Simple Interest = $1140

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 = $3800 + $1140

= $4940

Thus, Amount to be paid = $4940 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 = $3800

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3800 + ($3800 × 6% × 5)

= $3800 + ($3800 ×6/100 × 5)

= $3800 + (3800 × 6 × 5/100)

= $3800 + (22800 × 5/100)

= $3800 + (114000/100)

= $3800 + $1140 = $4940

Thus, Amount (A) to be paid = $4940 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3800, the simple interest in 1 year

= 6/100 × 3800

= 6 × 3800/100

= 22800/100 = $228

Thus, simple interest for 1 year = $228

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $228 × 5 = $1140

Thus, Simple Interest (SI) = $1140

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $1140

= $4940

Thus, Amount to be paid = $4940 Answer


Similar Questions

(1) Find the amount to be paid if Robert borrowed a sum of $5100 at 9% simple interest for 8 years.

(2) In how much time a principal of $3000 will amount to $3240 at a simple interest of 4% per annum?

(3) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 6% simple interest for 8 years.

(4) If Paul paid $5640 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(5) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 4% simple interest?

(6) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $10132 to clear the loan, then find the time period of the loan.

(7) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $10496 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 2% simple interest.

(9) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 2% simple interest.

(10) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8500 to clear the loan, then find the time period of the loan.


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