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) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 5% simple interest for 8 years.

(2) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $7546 to clear the loan, then find the time period of the loan.

(3) Richard took a loan of $5200 at the rate of 8% simple interest per annum. If he paid an amount of $8528 to clear the loan, then find the time period of the loan.

(4) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $10164 to clear the loan, then find the time period of the loan.

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

(6) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 6% simple interest?

(7) Calculate the amount due if William borrowed a sum of $3500 at 7% simple interest for 3 years.

(8) How much loan did Elizabeth borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6540 to clear it?

(9) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 5% simple interest?

(10) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 3% simple interest?


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