Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 10% simple interest.


Correct Answer  $9785

Solution And Explanation

Solution

Given,

Principal (P) = $5150

Rate of Simple Interest (SI) = 10%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 9

= $5150 ×10/100 × 9

= 5150 × 10 × 9/100

= 51500 × 9/100

= 463500/100

= $4635

Thus, Simple Interest = $4635

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 + $4635

= $9785

Thus, Amount to be paid = $9785 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) = 10%

And, Time (t) = 9 years

Thus, Amount (A)

= $5150 + ($5150 × 10% × 9)

= $5150 + ($5150 ×10/100 × 9)

= $5150 + (5150 × 10 × 9/100)

= $5150 + (51500 × 9/100)

= $5150 + (463500/100)

= $5150 + $4635 = $9785

Thus, Amount (A) to be paid = $9785 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $5150, the simple interest in 1 year

= 10/100 × 5150

= 10 × 5150/100

= 51500/100 = $515

Thus, simple interest for 1 year = $515

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $515 × 9 = $4635

Thus, Simple Interest (SI) = $4635

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5150 + $4635

= $9785

Thus, Amount to be paid = $9785 Answer


Similar Questions

(1) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 6% simple interest?

(2) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 8% simple interest?

(3) Nancy took a loan of $6300 at the rate of 9% simple interest per annum. If he paid an amount of $11403 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 7% simple interest.

(5) If James paid $3480 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(6) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9984 to clear the loan, then find the time period of the loan.

(7) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 5% simple interest?

(8) Charles took a loan of $5800 at the rate of 10% simple interest per annum. If he paid an amount of $11020 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 3% simple interest for 7 years.

(10) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $7952 to clear the loan, then find the time period of the loan.


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