Simple Interest
MCQs Math


Question:     Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 8 years.


Correct Answer  $7280

Solution And Explanation

Solution

Given,

Principal (P) = $5200

Rate of Simple Interest (SI) = 5%

Time (t) = 8 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) = $5200 × 5% × 8

= $5200 ×5/100 × 8

= 5200 × 5 × 8/100

= 26000 × 8/100

= 208000/100

= $2080

Thus, Simple Interest = $2080

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 = $5200 + $2080

= $7280

Thus, Amount to be paid = $7280 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 = $5200

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 8 years

Thus, Amount (A)

= $5200 + ($5200 × 5% × 8)

= $5200 + ($5200 ×5/100 × 8)

= $5200 + (5200 × 5 × 8/100)

= $5200 + (26000 × 8/100)

= $5200 + (208000/100)

= $5200 + $2080 = $7280

Thus, Amount (A) to be paid = $7280 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 $5200, the simple interest in 1 year

= 5/100 × 5200

= 5 × 5200/100

= 26000/100 = $260

Thus, simple interest for 1 year = $260

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $260 × 8 = $2080

Thus, Simple Interest (SI) = $2080

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5200 + $2080

= $7280

Thus, Amount to be paid = $7280 Answer


Similar Questions

(1) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 7% simple interest?

(2) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 9% simple interest.

(3) What amount will be due after 2 years if Anthony borrowed a sum of $3650 at a 5% simple interest?

(4) What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 6% simple interest?

(5) What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 5% simple interest?

(6) Richard took a loan of $5200 at the rate of 10% simple interest per annum. If he paid an amount of $9880 to clear the loan, then find the time period of the loan.

(7) William took a loan of $5000 at the rate of 7% simple interest per annum. If he paid an amount of $8150 to clear the loan, then find the time period of the loan.

(8) Nancy took a loan of $6300 at the rate of 8% simple interest per annum. If he paid an amount of $10332 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Linda borrowed a sum of $3350 at 7% simple interest for 4 years.

(10) Sarah took a loan of $5700 at the rate of 9% simple interest per annum. If he paid an amount of $8778 to clear the loan, then find the time period of the loan.


NCERT Solution and CBSE Notes for class twelve, eleventh, tenth, ninth, seventh, sixth, fifth, fourth and General Math for competitive Exams. ©