Simple Interest
MCQs Math


Question:     What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 3% simple interest?


Correct Answer  $4071

Solution And Explanation

Solution

Given,

Principal (P) = $3450

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 6

= $3450 ×3/100 × 6

= 3450 × 3 × 6/100

= 10350 × 6/100

= 62100/100

= $621

Thus, Simple Interest = $621

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 + $621

= $4071

Thus, Amount to be paid = $4071 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) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3450 + ($3450 × 3% × 6)

= $3450 + ($3450 ×3/100 × 6)

= $3450 + (3450 × 3 × 6/100)

= $3450 + (10350 × 6/100)

= $3450 + (62100/100)

= $3450 + $621 = $4071

Thus, Amount (A) to be paid = $4071 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3450, the simple interest in 1 year

= 3/100 × 3450

= 3 × 3450/100

= 10350/100 = $103.5

Thus, simple interest for 1 year = $103.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $103.5 × 6 = $621

Thus, Simple Interest (SI) = $621

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $621

= $4071

Thus, Amount to be paid = $4071 Answer


Similar Questions

(1) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $10132 to clear the loan, then find the time period of the loan.

(2) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 9% simple interest?

(3) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 6% simple interest?

(4) Charles took a loan of $5800 at the rate of 9% simple interest per annum. If he paid an amount of $8932 to clear the loan, then find the time period of the loan.

(5) John took a loan of $4400 at the rate of 6% simple interest per annum. If he paid an amount of $5984 to clear the loan, then find the time period of the loan.

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

(7) Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 8 years.

(8) Calculate the amount due if Patricia borrowed a sum of $3150 at 9% simple interest for 3 years.

(9) Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $12540 to clear the loan, then find the time period of the loan.

(10) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 6% simple interest?


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