Simple Interest
MCQs Math


Question:     What amount does John have to pay after 5 years if he takes a loan of $3200 at 6% simple interest?


Correct Answer  $4160

Solution And Explanation

Solution

Given,

Principal (P) = $3200

Rate of Simple Interest (SI) = 6%

Time (t) = 5 years

Thus, Amount (A) = ?

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

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

= $3200 ×6/100 × 5

= 3200 × 6 × 5/100

= 19200 × 5/100

= 96000/100

= $960

Thus, Simple Interest = $960

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 + $960

= $4160

Thus, Amount to be paid = $4160 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) = 6%

And, Time (t) = 5 years

Thus, Amount (A)

= $3200 + ($3200 × 6% × 5)

= $3200 + ($3200 ×6/100 × 5)

= $3200 + (3200 × 6 × 5/100)

= $3200 + (19200 × 5/100)

= $3200 + (96000/100)

= $3200 + $960 = $4160

Thus, Amount (A) to be paid = $4160 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3200, the simple interest in 1 year

= 6/100 × 3200

= 6 × 3200/100

= 19200/100 = $192

Thus, simple interest for 1 year = $192

Therefore, simple interest for 5 years

= Simple interest for 1 year × 5

= $192 × 5 = $960

Thus, Simple Interest (SI) = $960

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3200 + $960

= $4160

Thus, Amount to be paid = $4160 Answer


Similar Questions

(1) Calculate the amount due if Linda borrowed a sum of $3350 at 10% simple interest for 3 years.

(2) Find the amount to be paid if Jessica borrowed a sum of $5750 at 9% simple interest for 7 years.

(3) What amount does David have to pay after 5 years if he takes a loan of $3400 at 9% simple interest?

(4) Donald had to pay $4770 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $7224 to clear the loan, then find the time period of the loan.

(6) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $9976 to clear the loan, then find the time period of the loan.

(7) Margaret took a loan of $6700 at the rate of 8% simple interest per annum. If he paid an amount of $9916 to clear the loan, then find the time period of the loan.

(8) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $8976 to clear the loan, then find the time period of the loan.

(9) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $9472 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if Mary borrowed a sum of $5050 at 3% simple interest for 8 years.


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