Simple Interest
MCQs Math


Question:     What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 4% simple interest?


Correct Answer  $3782

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 4%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $3050 × 4% × 6

= $3050 ×4/100 × 6

= 3050 × 4 × 6/100

= 12200 × 6/100

= 73200/100

= $732

Thus, Simple Interest = $732

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 = $3050 + $732

= $3782

Thus, Amount to be paid = $3782 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 = $3050

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 6 years

Thus, Amount (A)

= $3050 + ($3050 × 4% × 6)

= $3050 + ($3050 ×4/100 × 6)

= $3050 + (3050 × 4 × 6/100)

= $3050 + (12200 × 6/100)

= $3050 + (73200/100)

= $3050 + $732 = $3782

Thus, Amount (A) to be paid = $3782 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = 4/100

∴ For $3050, the simple interest in 1 year

= 4/100 × 3050

= 4 × 3050/100

= 12200/100 = $122

Thus, simple interest for 1 year = $122

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $122 × 6 = $732

Thus, Simple Interest (SI) = $732

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $732

= $3782

Thus, Amount to be paid = $3782 Answer


Similar Questions

(1) Robert took a loan of $4200 at the rate of 7% simple interest per annum. If he paid an amount of $6846 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if Susan borrowed a sum of $5650 at 6% simple interest for 8 years.

(3) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 9% simple interest?

(4) Find the amount to be paid if Susan borrowed a sum of $5650 at 4% simple interest for 7 years.

(5) Elizabeth took a loan of $4900 at the rate of 7% simple interest per annum. If he paid an amount of $8330 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Jessica borrowed a sum of $3750 at 3% simple interest for 4 years.

(7) Calculate the amount due if John borrowed a sum of $3200 at 7% simple interest for 3 years.

(8) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 3% simple interest.

(9) James had to pay $3180 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(10) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 4% simple interest.


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