Simple Interest
MCQs Math


Question:     What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 2% simple interest?


Correct Answer  $3355

Solution And Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 2%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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 × 2% × 5

= $3050 ×2/100 × 5

= 3050 × 2 × 5/100

= 6100 × 5/100

= 30500/100

= $305

Thus, Simple Interest = $305

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 + $305

= $3355

Thus, Amount to be paid = $3355 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) = 2%

And, Time (t) = 5 years

Thus, Amount (A)

= $3050 + ($3050 × 2% × 5)

= $3050 + ($3050 ×2/100 × 5)

= $3050 + (3050 × 2 × 5/100)

= $3050 + (6100 × 5/100)

= $3050 + (30500/100)

= $3050 + $305 = $3355

Thus, Amount (A) to be paid = $3355 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = 2/100

∴ For $3050, the simple interest in 1 year

= 2/100 × 3050

= 2 × 3050/100

= 6100/100 = $61

Thus, simple interest for 1 year = $61

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $61 × 5 = $305

Thus, Simple Interest (SI) = $305

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $305

= $3355

Thus, Amount to be paid = $3355 Answer


Similar Questions

(1) Linda took a loan of $4700 at the rate of 8% simple interest per annum. If he paid an amount of $8084 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 7% simple interest.

(3) Calculate the amount due if Susan borrowed a sum of $3650 at 7% simple interest for 4 years.

(4) Barbara took a loan of $5100 at the rate of 10% simple interest per annum. If he paid an amount of $8670 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 7% simple interest.

(6) How much loan did Donald borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7800 to clear it?

(7) Thomas had to pay $4256 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(8) Find the amount to be paid if Patricia borrowed a sum of $5150 at 4% simple interest for 7 years.

(9) Nancy took a loan of $6300 at the rate of 7% simple interest per annum. If he paid an amount of $10710 to clear the loan, then find the time period of the loan.

(10) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $9231 to clear the loan, then find the time period of the loan.


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