Simple Interest
MCQs Math


Question:     What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 5% simple interest?


Correct Answer  $4485

Solution And Explanation

Solution

Given,

Principal (P) = $3450

Rate of Simple Interest (SI) = 5%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 6

= $3450 ×5/100 × 6

= 3450 × 5 × 6/100

= 17250 × 6/100

= 103500/100

= $1035

Thus, Simple Interest = $1035

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 + $1035

= $4485

Thus, Amount to be paid = $4485 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) = 5%

And, Time (t) = 6 years

Thus, Amount (A)

= $3450 + ($3450 × 5% × 6)

= $3450 + ($3450 ×5/100 × 6)

= $3450 + (3450 × 5 × 6/100)

= $3450 + (17250 × 6/100)

= $3450 + (103500/100)

= $3450 + $1035 = $4485

Thus, Amount (A) to be paid = $4485 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $3450, the simple interest in 1 year

= 5/100 × 3450

= 5 × 3450/100

= 17250/100 = $172.5

Thus, simple interest for 1 year = $172.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $172.5 × 6 = $1035

Thus, Simple Interest (SI) = $1035

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $1035

= $4485

Thus, Amount to be paid = $4485 Answer


Similar Questions

(1) Calculate the amount due after 9 years if Susan borrowed a sum of $5650 at a rate of 2% simple interest.

(2) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 8% simple interest?

(3) Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 8% simple interest.

(4) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $7810 to clear the loan, then find the time period of the loan.

(5) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 3% simple interest for 8 years.

(6) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 6% simple interest?

(7) Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $8364 to clear the loan, then find the time period of the loan.

(8) Kimberly had to pay $4929 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) What amount does James have to pay after 5 years if he takes a loan of $3000 at 4% simple interest?

(10) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 5% simple interest.


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