Simple Interest
MCQs Math


Question:     Calculate the amount due if William borrowed a sum of $3500 at 6% simple interest for 4 years.


Correct Answer  $4340

Solution And Explanation

Solution

Given,

Principal (P) = $3500

Rate of Simple Interest (SI) = 6%

Time (t) = 4 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3500 × 6% × 4

= $3500 ×6/100 × 4

= 3500 × 6 × 4/100

= 21000 × 4/100

= 84000/100

= $840

Thus, Simple Interest = $840

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 = $3500 + $840

= $4340

Thus, Amount to be paid = $4340 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 = $3500

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 4 years

Thus, Amount (A)

= $3500 + ($3500 × 6% × 4)

= $3500 + ($3500 ×6/100 × 4)

= $3500 + (3500 × 6 × 4/100)

= $3500 + (21000 × 4/100)

= $3500 + (84000/100)

= $3500 + $840 = $4340

Thus, Amount (A) to be paid = $4340 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = 6/100

∴ For $3500, the simple interest in 1 year

= 6/100 × 3500

= 6 × 3500/100

= 21000/100 = $210

Thus, simple interest for 1 year = $210

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $210 × 4 = $840

Thus, Simple Interest (SI) = $840

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3500 + $840

= $4340

Thus, Amount to be paid = $4340 Answer


Similar Questions

(1) Find the amount to be paid if David borrowed a sum of $5400 at 4% simple interest for 7 years.

(2) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 9% simple interest?

(3) Find the amount to be paid if Michael borrowed a sum of $5300 at 7% simple interest for 8 years.

(4) Sandra took a loan of $6900 at the rate of 8% simple interest per annum. If he paid an amount of $11316 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Jessica borrowed a sum of $3750 at 7% simple interest for 4 years.

(6) Joseph took a loan of $5400 at the rate of 9% simple interest per annum. If he paid an amount of $8316 to clear the loan, then find the time period of the loan.

(7) Find the amount to be paid if Linda borrowed a sum of $5350 at 9% simple interest for 8 years.

(8) If Barbara borrowed $3550 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(9) Charles took a loan of $5800 at the rate of 7% simple interest per annum. If he paid an amount of $9860 to clear the loan, then find the time period of the loan.

(10) How much loan did Robert borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $5865 to clear it?


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