Simple Interest
MCQs Math


Question:     What amount does Sarah have to pay after 6 years if he takes a loan of $3850 at 9% simple interest?


Correct Answer  $5929

Solution And Explanation

Solution

Given,

Principal (P) = $3850

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) = $3850 × 9% × 6

= $3850 ×9/100 × 6

= 3850 × 9 × 6/100

= 34650 × 6/100

= 207900/100

= $2079

Thus, Simple Interest = $2079

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 = $3850 + $2079

= $5929

Thus, Amount to be paid = $5929 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 = $3850

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3850 + ($3850 × 9% × 6)

= $3850 + ($3850 ×9/100 × 6)

= $3850 + (3850 × 9 × 6/100)

= $3850 + (34650 × 6/100)

= $3850 + (207900/100)

= $3850 + $2079 = $5929

Thus, Amount (A) to be paid = $5929 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 $3850, the simple interest in 1 year

= 9/100 × 3850

= 9 × 3850/100

= 34650/100 = $346.5

Thus, simple interest for 1 year = $346.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $346.5 × 6 = $2079

Thus, Simple Interest (SI) = $2079

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $2079

= $5929

Thus, Amount to be paid = $5929 Answer


Similar Questions

(1) How much loan did Donna borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8562.5 to clear it?

(2) If Jennifer borrowed $3250 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(3) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.

(4) Calculate the amount due if Charles borrowed a sum of $3900 at 2% simple interest for 3 years.

(5) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 7% simple interest?

(6) Linda took a loan of $4700 at the rate of 6% simple interest per annum. If he paid an amount of $6392 to clear the loan, then find the time period of the loan.

(7) How much loan did Patricia borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6180 to clear it?

(8) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 9% simple interest?

(9) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $6880 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if James borrowed a sum of $5000 at 2% simple interest for 8 years.


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