Simple Interest
MCQs Math


Question:     What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 5% simple interest?


Correct Answer  $5135

Solution And Explanation

Solution

Given,

Principal (P) = $3950

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) = $3950 × 5% × 6

= $3950 ×5/100 × 6

= 3950 × 5 × 6/100

= 19750 × 6/100

= 118500/100

= $1185

Thus, Simple Interest = $1185

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 = $3950 + $1185

= $5135

Thus, Amount to be paid = $5135 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 = $3950

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3950 + ($3950 × 5% × 6)

= $3950 + ($3950 ×5/100 × 6)

= $3950 + (3950 × 5 × 6/100)

= $3950 + (19750 × 6/100)

= $3950 + (118500/100)

= $3950 + $1185 = $5135

Thus, Amount (A) to be paid = $5135 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 $3950, the simple interest in 1 year

= 5/100 × 3950

= 5 × 3950/100

= 19750/100 = $197.5

Thus, simple interest for 1 year = $197.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $197.5 × 6 = $1185

Thus, Simple Interest (SI) = $1185

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3950 + $1185

= $5135

Thus, Amount to be paid = $5135 Answer


Similar Questions

(1) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 2% simple interest?

(2) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 6% simple interest?

(3) Find the amount to be paid if Barbara borrowed a sum of $5550 at 5% simple interest for 8 years.

(4) Michael took a loan of $4600 at the rate of 6% simple interest per annum. If he paid an amount of $6256 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 10% simple interest.

(6) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 10% simple interest?

(7) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $10640 to clear the loan, then find the time period of the loan.

(8) 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.

(9) Calculate the amount due if John borrowed a sum of $3200 at 4% simple interest for 4 years.

(10) Emily had to pay $5177.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.


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