Simple Interest
MCQs Math


Question:     What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 10% simple interest?


Correct Answer  $5040

Solution And Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 10%

Time (t) = 6 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) = $3150 × 10% × 6

= $3150 ×10/100 × 6

= 3150 × 10 × 6/100

= 31500 × 6/100

= 189000/100

= $1890

Thus, Simple Interest = $1890

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 + $1890

= $5040

Thus, Amount to be paid = $5040 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) = 10%

And, Time (t) = 6 years

Thus, Amount (A)

= $3150 + ($3150 × 10% × 6)

= $3150 + ($3150 ×10/100 × 6)

= $3150 + (3150 × 10 × 6/100)

= $3150 + (31500 × 6/100)

= $3150 + (189000/100)

= $3150 + $1890 = $5040

Thus, Amount (A) to be paid = $5040 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 $3150, the simple interest in 1 year

= 10/100 × 3150

= 10 × 3150/100

= 31500/100 = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $315 × 6 = $1890

Thus, Simple Interest (SI) = $1890

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $1890

= $5040

Thus, Amount to be paid = $5040 Answer


Similar Questions

(1) Find the amount to be paid if Karen borrowed a sum of $5950 at 9% simple interest for 8 years.

(2) Find the amount to be paid if Richard borrowed a sum of $5600 at 7% simple interest for 8 years.

(3) If Barbara borrowed $3550 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(4) Nancy had to pay $4399 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 6% simple interest.

(6) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.

(7) Linda took a loan of $4700 at the rate of 9% simple interest per annum. If he paid an amount of $8930 to clear the loan, then find the time period of the loan.

(8) If Linda paid $4020 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) Daniel took a loan of $6200 at the rate of 7% simple interest per annum. If he paid an amount of $10106 to clear the loan, then find the time period of the loan.

(10) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 6% simple interest?


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©