Simple Interest
MCQs Math


Question:     If John borrowed $3200 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.


Correct Answer  $3328

Solution And Explanation

Solution

Given,

Principal (P) = $3200

Rate of Simple Interest (SI) = 2%

Time (t) = 2 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) = $3200 × 2% × 2

= $3200 ×2/100 × 2

= 3200 × 2 × 2/100

= 6400 × 2/100

= 12800/100

= $128

Thus, Simple Interest = $128

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 + $128

= $3328

Thus, Amount to be paid = $3328 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) = 2%

And, Time (t) = 2 years

Thus, Amount (A)

= $3200 + ($3200 × 2% × 2)

= $3200 + ($3200 ×2/100 × 2)

= $3200 + (3200 × 2 × 2/100)

= $3200 + (6400 × 2/100)

= $3200 + (12800/100)

= $3200 + $128 = $3328

Thus, Amount (A) to be paid = $3328 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 in 1 year = $2

∴ For $1, the simple interest in 1 year = 2/100

∴ For $3200, the simple interest in 1 year

= 2/100 × 3200

= 2 × 3200/100

= 6400/100 = $64

Thus, simple interest in 1 year = $64

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $64 × 2 = $128

Thus, Simple Interest (SI) = $128

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3200 + $128

= $3328

Thus, Amount to be paid = $3328 Answer


Similar Questions

(1) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $10640 to clear the loan, then find the time period of the loan.

(2) Joseph took a loan of $5400 at the rate of 6% simple interest per annum. If he paid an amount of $7344 to clear the loan, then find the time period of the loan.

(3) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 10% simple interest?

(4) If Karen borrowed $3950 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(5) Margaret took a loan of $6700 at the rate of 6% simple interest per annum. If he paid an amount of $10720 to clear the loan, then find the time period of the loan.

(6) How much loan did Jessica borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6612.5 to clear it?

(7) What amount does James have to pay after 6 years if he takes a loan of $3000 at 6% simple interest?

(8) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 7% simple interest.

(9) 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.

(10) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $8802 to clear the loan, then find the time period of the loan.


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