Simple Interest
MCQs Math


Question:     What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 6% simple interest?


Correct Answer  $4095

Solution And Explanation

Solution

Given,

Principal (P) = $3150

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) = $3150 × 6% × 5

= $3150 ×6/100 × 5

= 3150 × 6 × 5/100

= 18900 × 5/100

= 94500/100

= $945

Thus, Simple Interest = $945

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 = $3150 + $945

= $4095

Thus, Amount to be paid = $4095 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 = $3150

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

And, Time (t) = 5 years

Thus, Amount (A)

= $3150 + ($3150 × 6% × 5)

= $3150 + ($3150 ×6/100 × 5)

= $3150 + (3150 × 6 × 5/100)

= $3150 + (18900 × 5/100)

= $3150 + (94500/100)

= $3150 + $945 = $4095

Thus, Amount (A) to be paid = $4095 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 $3150, the simple interest in 1 year

= 6/100 × 3150

= 6 × 3150/100

= 18900/100 = $189

Thus, simple interest for 1 year = $189

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $189 × 5 = $945

Thus, Simple Interest (SI) = $945

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $945

= $4095

Thus, Amount to be paid = $4095 Answer


Similar Questions

(1) Calculate the amount due if Susan borrowed a sum of $3650 at 5% simple interest for 3 years.

(2) If Andrew paid $5376 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(3) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 4 years.

(4) Patricia took a loan of $4300 at the rate of 9% simple interest per annum. If he paid an amount of $6622 to clear the loan, then find the time period of the loan.

(5) If Anthony paid $5160 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(6) Lisa took a loan of $6100 at the rate of 9% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.

(7) Karen took a loan of $5900 at the rate of 7% simple interest per annum. If he paid an amount of $8791 to clear the loan, then find the time period of the loan.

(8) Sandra took a loan of $6900 at the rate of 6% simple interest per annum. If he paid an amount of $11040 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 10% simple interest.

(10) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $10860 to clear the loan, then find the time period of the loan.


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