Simple Interest
MCQs Math


Question:     Find the amount to be paid if Patricia borrowed a sum of $5150 at 3% simple interest for 8 years.


Correct Answer  $6386

Solution And Explanation

Solution

Given,

Principal (P) = $5150

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) = $5150 × 3% × 8

= $5150 ×3/100 × 8

= 5150 × 3 × 8/100

= 15450 × 8/100

= 123600/100

= $1236

Thus, Simple Interest = $1236

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 = $5150 + $1236

= $6386

Thus, Amount to be paid = $6386 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 = $5150

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

And, Time (t) = 8 years

Thus, Amount (A)

= $5150 + ($5150 × 3% × 8)

= $5150 + ($5150 ×3/100 × 8)

= $5150 + (5150 × 3 × 8/100)

= $5150 + (15450 × 8/100)

= $5150 + (123600/100)

= $5150 + $1236 = $6386

Thus, Amount (A) to be paid = $6386 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 $5150, the simple interest in 1 year

= 3/100 × 5150

= 3 × 5150/100

= 15450/100 = $154.5

Thus, simple interest for 1 year = $154.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $154.5 × 8 = $1236

Thus, Simple Interest (SI) = $1236

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5150 + $1236

= $6386

Thus, Amount to be paid = $6386 Answer


Similar Questions

(1) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 7% simple interest?

(3) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 8% simple interest?

(4) Calculate the amount due if Christopher borrowed a sum of $4000 at 7% simple interest for 3 years.

(5) Find the amount to be paid if Barbara borrowed a sum of $5550 at 5% simple interest for 8 years.

(6) Thomas had to pay $4370 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(7) Find the amount to be paid if Mary borrowed a sum of $5050 at 2% simple interest for 7 years.

(8) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 4% simple interest?

(9) Robert took a loan of $4200 at the rate of 8% simple interest per annum. If he paid an amount of $6888 to clear the loan, then find the time period of the loan.

(10) Matthew took a loan of $6400 at the rate of 6% simple interest per annum. If he paid an amount of $9472 to clear the loan, then find the time period of the loan.


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