Simple Interest
MCQs Math


Question:     What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 10% simple interest?


Correct Answer  $5520

Solution And Explanation

Solution

Given,

Principal (P) = $3450

Rate of Simple Interest (SI) = 10%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 6

= $3450 ×10/100 × 6

= 3450 × 10 × 6/100

= 34500 × 6/100

= 207000/100

= $2070

Thus, Simple Interest = $2070

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 + $2070

= $5520

Thus, Amount to be paid = $5520 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) = 10%

And, Time (t) = 6 years

Thus, Amount (A)

= $3450 + ($3450 × 10% × 6)

= $3450 + ($3450 ×10/100 × 6)

= $3450 + (3450 × 10 × 6/100)

= $3450 + (34500 × 6/100)

= $3450 + (207000/100)

= $3450 + $2070 = $5520

Thus, Amount (A) to be paid = $5520 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $3450, the simple interest in 1 year

= 10/100 × 3450

= 10 × 3450/100

= 34500/100 = $345

Thus, simple interest for 1 year = $345

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $345 × 6 = $2070

Thus, Simple Interest (SI) = $2070

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3450 + $2070

= $5520

Thus, Amount to be paid = $5520 Answer


Similar Questions

(1) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 8% simple interest?

(2) Find the amount to be paid if Michael borrowed a sum of $5300 at 8% simple interest for 8 years.

(3) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 2% simple interest?

(4) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 4% simple interest?

(5) Find the amount to be paid if John borrowed a sum of $5200 at 8% simple interest for 7 years.

(6) Betty had to pay $4760 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(7) If Mark paid $4752 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(8) Find the amount to be paid if Michael borrowed a sum of $5300 at 6% simple interest for 8 years.

(9) If Mary paid $3416 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(10) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $9798 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. ©