Simple Interest
MCQs Math


Question:     What amount does John have to pay after 5 years if he takes a loan of $3200 at 10% simple interest?


Correct Answer  $4800

Solution And Explanation

Solution

Given,

Principal (P) = $3200

Rate of Simple Interest (SI) = 10%

Time (t) = 5 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3200 × 10% × 5

= $3200 ×10/100 × 5

= 3200 × 10 × 5/100

= 32000 × 5/100

= 160000/100

= $1600

Thus, Simple Interest = $1600

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 = $3200 + $1600

= $4800

Thus, Amount to be paid = $4800 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 = $3200

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 5 years

Thus, Amount (A)

= $3200 + ($3200 × 10% × 5)

= $3200 + ($3200 ×10/100 × 5)

= $3200 + (3200 × 10 × 5/100)

= $3200 + (32000 × 5/100)

= $3200 + (160000/100)

= $3200 + $1600 = $4800

Thus, Amount (A) to be paid = $4800 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $3200, the simple interest in 1 year

= 10/100 × 3200

= 10 × 3200/100

= 32000/100 = $320

Thus, simple interest for 1 year = $320

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $320 × 5 = $1600

Thus, Simple Interest (SI) = $1600

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3200 + $1600

= $4800

Thus, Amount to be paid = $4800 Answer


Similar Questions

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

(2) If Paul paid $5640 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $8296 to clear the loan, then find the time period of the loan.

(4) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 8% simple interest?

(5) Calculate the amount due if Robert borrowed a sum of $3100 at 10% simple interest for 4 years.

(6) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $11696 to clear the loan, then find the time period of the loan.

(7) Linda took a loan of $4700 at the rate of 10% simple interest per annum. If he paid an amount of $8930 to clear the loan, then find the time period of the loan.

(8) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 10% simple interest?

(9) How much loan did Lisa borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7562.5 to clear it?

(10) Betty took a loan of $6500 at the rate of 7% simple interest per annum. If he paid an amount of $9230 to clear the loan, then find the time period of the loan.


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