Simple Interest
MCQs Math


Question:     What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 5% simple interest?


Correct Answer  $4940

Solution And Explanation

Solution

Given,

Principal (P) = $3800

Rate of Simple Interest (SI) = 5%

Time (t) = 6 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) = $3800 × 5% × 6

= $3800 ×5/100 × 6

= 3800 × 5 × 6/100

= 19000 × 6/100

= 114000/100

= $1140

Thus, Simple Interest = $1140

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 = $3800 + $1140

= $4940

Thus, Amount to be paid = $4940 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 = $3800

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3800 + ($3800 × 5% × 6)

= $3800 + ($3800 ×5/100 × 6)

= $3800 + (3800 × 5 × 6/100)

= $3800 + (19000 × 6/100)

= $3800 + (114000/100)

= $3800 + $1140 = $4940

Thus, Amount (A) to be paid = $4940 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 $3800, the simple interest in 1 year

= 5/100 × 3800

= 5 × 3800/100

= 19000/100 = $190

Thus, simple interest for 1 year = $190

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $190 × 6 = $1140

Thus, Simple Interest (SI) = $1140

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $1140

= $4940

Thus, Amount to be paid = $4940 Answer


Similar Questions

(1) If Barbara paid $3834 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(2) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 9% simple interest?

(3) What amount does Jennifer have to pay after 6 years if he takes a loan of $3250 at 4% simple interest?

(4) Christopher had to pay $4480 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(5) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 5% simple interest?

(6) How much loan did Michelle borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7645 to clear it?

(7) Sarah had to pay $4312 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(8) Sarah took a loan of $5700 at the rate of 6% 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 Linda borrowed a sum of $5350 at 5% simple interest for 8 years.

(10) 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.


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