Simple Interest
MCQs Math


Question:     What amount does James have to pay after 5 years if he takes a loan of $3000 at 3% simple interest?


Correct Answer  $3450

Solution And Explanation

Solution

Given,

Principal (P) = $3000

Rate of Simple Interest (SI) = 3%

Time (t) = 5 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) = $3000 × 3% × 5

= $3000 ×3/100 × 5

= 3000 × 3 × 5/100

= 9000 × 5/100

= 45000/100

= $450

Thus, Simple Interest = $450

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 = $3000 + $450

= $3450

Thus, Amount to be paid = $3450 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 = $3000

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 5 years

Thus, Amount (A)

= $3000 + ($3000 × 3% × 5)

= $3000 + ($3000 ×3/100 × 5)

= $3000 + (3000 × 3 × 5/100)

= $3000 + (9000 × 5/100)

= $3000 + (45000/100)

= $3000 + $450 = $3450

Thus, Amount (A) to be paid = $3450 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 $3000, the simple interest in 1 year

= 3/100 × 3000

= 3 × 3000/100

= 9000/100 = $90

Thus, simple interest for 1 year = $90

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $90 × 5 = $450

Thus, Simple Interest (SI) = $450

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3000 + $450

= $3450

Thus, Amount to be paid = $3450 Answer


Similar Questions

(1) If Patricia paid $3654 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(2) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 8% simple interest?

(3) Find the amount to be paid if Mary borrowed a sum of $5050 at 10% simple interest for 7 years.

(4) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 3% simple interest.

(5) Calculate the amount due if Karen borrowed a sum of $3950 at 5% simple interest for 4 years.

(6) Calculate the amount due if Susan borrowed a sum of $3650 at 6% simple interest for 3 years.

(7) If Sarah borrowed $3850 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(8) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 4% simple interest.

(9) Find the amount to be paid if David borrowed a sum of $5400 at 5% simple interest for 8 years.

(10) If Charles paid $4524 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.


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