Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 6% simple interest.


Correct Answer  $8624

Solution And Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 6%

Time (t) = 9 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) = $5600 × 6% × 9

= $5600 ×6/100 × 9

= 5600 × 6 × 9/100

= 33600 × 9/100

= 302400/100

= $3024

Thus, Simple Interest = $3024

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 = $5600 + $3024

= $8624

Thus, Amount to be paid = $8624 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 = $5600

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 9 years

Thus, Amount (A)

= $5600 + ($5600 × 6% × 9)

= $5600 + ($5600 ×6/100 × 9)

= $5600 + (5600 × 6 × 9/100)

= $5600 + (33600 × 9/100)

= $5600 + (302400/100)

= $5600 + $3024 = $8624

Thus, Amount (A) to be paid = $8624 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 $5600, the simple interest in 1 year

= 6/100 × 5600

= 6 × 5600/100

= 33600/100 = $336

Thus, simple interest for 1 year = $336

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $336 × 9 = $3024

Thus, Simple Interest (SI) = $3024

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $3024

= $8624

Thus, Amount to be paid = $8624 Answer


Similar Questions

(1) Calculate the amount due if Susan borrowed a sum of $3650 at 8% simple interest for 3 years.

(2) David took a loan of $4800 at the rate of 8% simple interest per annum. If he paid an amount of $7104 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 9 years if Mary borrowed a sum of $5050 at a rate of 7% simple interest.

(4) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 6% simple interest?

(5) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.

(6) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 5% simple interest?

(7) Sarah had to pay $4081 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(8) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 3% simple interest for 7 years.

(9) John had to pay $3680 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(10) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9088 to clear the loan, then find the time period of the loan.


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