Simple Interest
MCQs Math


Question:     What amount does Elizabeth have to pay after 5 years if he takes a loan of $3450 at 2% simple interest?


Correct Answer  $3795

Solution And Explanation

Solution

Given,

Principal (P) = $3450

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) = $3450 × 2% × 5

= $3450 ×2/100 × 5

= 3450 × 2 × 5/100

= 6900 × 5/100

= 34500/100

= $345

Thus, Simple Interest = $345

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 = $3450 + $345

= $3795

Thus, Amount to be paid = $3795 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 = $3450

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 5 years

Thus, Amount (A)

= $3450 + ($3450 × 2% × 5)

= $3450 + ($3450 ×2/100 × 5)

= $3450 + (3450 × 2 × 5/100)

= $3450 + (6900 × 5/100)

= $3450 + (34500/100)

= $3450 + $345 = $3795

Thus, Amount (A) to be paid = $3795 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 $3450, the simple interest in 1 year

= 2/100 × 3450

= 2 × 3450/100

= 6900/100 = $69

Thus, simple interest for 1 year = $69

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $69 × 5 = $345

Thus, Simple Interest (SI) = $345

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $345

= $3795

Thus, Amount to be paid = $3795 Answer


Similar Questions

(1) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $9120 to clear the loan, then find the time period of the loan.

(2) What amount will be due after 2 years if Joseph borrowed a sum of $3350 at a 6% simple interest?

(3) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 10% simple interest?

(4) Calculate the amount due if Jessica borrowed a sum of $3750 at 7% simple interest for 3 years.

(5) Calculate the amount due if Thomas borrowed a sum of $3800 at 4% simple interest for 3 years.

(6) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $9128 to clear the loan, then find the time period of the loan.

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

(8) Donald took a loan of $7000 at the rate of 8% simple interest per annum. If he paid an amount of $10920 to clear the loan, then find the time period of the loan.

(9) Joseph took a loan of $5400 at the rate of 6% simple interest per annum. If he paid an amount of $7668 to clear the loan, then find the time period of the loan.

(10) In how much time a principal of $3200 will amount to $3840 at a simple interest of 4% per annum?


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