Simple Interest
MCQs Math


Question:     Find the amount to be paid if Charles borrowed a sum of $5900 at 10% simple interest for 7 years.


Correct Answer  $10030

Solution And Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 10%

Time (t) = 7 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) = $5900 × 10% × 7

= $5900 ×10/100 × 7

= 5900 × 10 × 7/100

= 59000 × 7/100

= 413000/100

= $4130

Thus, Simple Interest = $4130

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 = $5900 + $4130

= $10030

Thus, Amount to be paid = $10030 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 = $5900

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 7 years

Thus, Amount (A)

= $5900 + ($5900 × 10% × 7)

= $5900 + ($5900 ×10/100 × 7)

= $5900 + (5900 × 10 × 7/100)

= $5900 + (59000 × 7/100)

= $5900 + (413000/100)

= $5900 + $4130 = $10030

Thus, Amount (A) to be paid = $10030 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 $5900, the simple interest in 1 year

= 10/100 × 5900

= 10 × 5900/100

= 59000/100 = $590

Thus, simple interest for 1 year = $590

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $590 × 7 = $4130

Thus, Simple Interest (SI) = $4130

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $4130

= $10030

Thus, Amount to be paid = $10030 Answer


Similar Questions

(1) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11780 to clear the loan, then find the time period of the loan.

(2) Lisa had to pay $4414.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(3) William took a loan of $5000 at the rate of 6% simple interest per annum. If he paid an amount of $7700 to clear the loan, then find the time period of the loan.

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

(5) How much loan did David borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6480 to clear it?

(6) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.

(7) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 8% simple interest?

(8) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $9460 to clear the loan, then find the time period of the loan.

(9) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $8880 to clear the loan, then find the time period of the loan.

(10) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $10260 to clear the loan, then find the time period of the loan.


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