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 Joseph have to pay after 6 years if he takes a loan of $3700 at 7% simple interest?

(2) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $8256 to clear the loan, then find the time period of the loan.

(3) If Daniel paid $4428 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(4) If Lisa paid $4374 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(5) Calculate the amount due if Jennifer borrowed a sum of $3250 at 5% simple interest for 4 years.

(6) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 7% simple interest?

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

(8) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $9120 to clear the loan, then find the time period of the loan.

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

(10) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 5% simple interest.


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