Simple Interest
MCQs Math


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


Correct Answer  $4148

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 6%

Time (t) = 6 years

Thus, Amount (A) = ?

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

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

= $3050 ×6/100 × 6

= 3050 × 6 × 6/100

= 18300 × 6/100

= 109800/100

= $1098

Thus, Simple Interest = $1098

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 + $1098

= $4148

Thus, Amount to be paid = $4148 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) = 6%

And, Time (t) = 6 years

Thus, Amount (A)

= $3050 + ($3050 × 6% × 6)

= $3050 + ($3050 ×6/100 × 6)

= $3050 + (3050 × 6 × 6/100)

= $3050 + (18300 × 6/100)

= $3050 + (109800/100)

= $3050 + $1098 = $4148

Thus, Amount (A) to be paid = $4148 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3050, the simple interest in 1 year

= 6/100 × 3050

= 6 × 3050/100

= 18300/100 = $183

Thus, simple interest for 1 year = $183

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $183 × 6 = $1098

Thus, Simple Interest (SI) = $1098

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $1098

= $4148

Thus, Amount to be paid = $4148 Answer


Similar Questions

(1) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.

(2) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $7912 to clear the loan, then find the time period of the loan.

(3) How much loan did Nancy borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7072.5 to clear it?

(4) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 7 years.

(5) How much loan did Cynthia borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9540 to clear it?

(6) James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $7600 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 7% simple interest.

(8) Find the amount to be paid if Sarah borrowed a sum of $5850 at 3% simple interest for 8 years.

(9) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 5% simple interest.

(10) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 4% simple interest.


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