Simple Interest
MCQs Math


Question:     What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 9% simple interest?


Correct Answer  $5313

Solution And Explanation

Solution

Given,

Principal (P) = $3450

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3450 × 9% × 6

= $3450 ×9/100 × 6

= 3450 × 9 × 6/100

= 31050 × 6/100

= 186300/100

= $1863

Thus, Simple Interest = $1863

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 = $3450 + $1863

= $5313

Thus, Amount to be paid = $5313 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 = $3450

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3450 + ($3450 × 9% × 6)

= $3450 + ($3450 ×9/100 × 6)

= $3450 + (3450 × 9 × 6/100)

= $3450 + (31050 × 6/100)

= $3450 + (186300/100)

= $3450 + $1863 = $5313

Thus, Amount (A) to be paid = $5313 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3450, the simple interest in 1 year

= 9/100 × 3450

= 9 × 3450/100

= 31050/100 = $310.5

Thus, simple interest for 1 year = $310.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $310.5 × 6 = $1863

Thus, Simple Interest (SI) = $1863

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $1863

= $5313

Thus, Amount to be paid = $5313 Answer


Similar Questions

(1) How much loan did Andrew borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7820 to clear it?

(2) What amount does James have to pay after 6 years if he takes a loan of $3000 at 8% simple interest?

(3) How much loan did Jennifer borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6300 to clear it?

(4) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9984 to clear the loan, then find the time period of the loan.

(5) In how much time a principal of $3200 will amount to $3456 at a simple interest of 4% per annum?

(6) How much loan did Carol borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8107.5 to clear it?

(7) What amount does David have to pay after 6 years if he takes a loan of $3400 at 8% simple interest?

(8) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 5% simple interest for 3 years.

(9) How much loan did Ryan borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9875 to clear it?

(10) Calculate the amount due if Sarah borrowed a sum of $3850 at 4% simple interest for 3 years.


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