Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Susan borrowed a sum of $5650 at a rate of 10% simple interest.


Correct Answer  $10735

Solution And Explanation

Solution

Given,

Principal (P) = $5650

Rate of Simple Interest (SI) = 10%

Time (t) = 9 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) = $5650 × 10% × 9

= $5650 ×10/100 × 9

= 5650 × 10 × 9/100

= 56500 × 9/100

= 508500/100

= $5085

Thus, Simple Interest = $5085

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 = $5650 + $5085

= $10735

Thus, Amount to be paid = $10735 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 = $5650

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 9 years

Thus, Amount (A)

= $5650 + ($5650 × 10% × 9)

= $5650 + ($5650 ×10/100 × 9)

= $5650 + (5650 × 10 × 9/100)

= $5650 + (56500 × 9/100)

= $5650 + (508500/100)

= $5650 + $5085 = $10735

Thus, Amount (A) to be paid = $10735 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 $5650, the simple interest in 1 year

= 10/100 × 5650

= 10 × 5650/100

= 56500/100 = $565

Thus, simple interest for 1 year = $565

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $565 × 9 = $5085

Thus, Simple Interest (SI) = $5085

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5650 + $5085

= $10735

Thus, Amount to be paid = $10735 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 10% simple interest.

(2) What amount does James have to pay after 6 years if he takes a loan of $3000 at 7% simple interest?

(3) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 8% simple interest.

(4) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 3% simple interest?

(5) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $12920 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Richard borrowed a sum of $3600 at 2% simple interest for 4 years.

(7) Calculate the amount due if John borrowed a sum of $3200 at 8% simple interest for 4 years.

(8) Jessica took a loan of $5500 at the rate of 10% simple interest per annum. If he paid an amount of $11000 to clear the loan, then find the time period of the loan.

(9) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7315 to clear it?

(10) Betty took a loan of $6500 at the rate of 7% simple interest per annum. If he paid an amount of $11050 to clear the loan, then find the time period of the loan.


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