Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 8% simple interest.


Correct Answer  $9030

Solution And Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 8%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $5250 × 8% × 9

= $5250 ×8/100 × 9

= 5250 × 8 × 9/100

= 42000 × 9/100

= 378000/100

= $3780

Thus, Simple Interest = $3780

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 = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 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 = $5250

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 9 years

Thus, Amount (A)

= $5250 + ($5250 × 8% × 9)

= $5250 + ($5250 ×8/100 × 9)

= $5250 + (5250 × 8 × 9/100)

= $5250 + (42000 × 9/100)

= $5250 + (378000/100)

= $5250 + $3780 = $9030

Thus, Amount (A) to be paid = $9030 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $5250, the simple interest in 1 year

= 8/100 × 5250

= 8 × 5250/100

= 42000/100 = $420

Thus, simple interest for 1 year = $420

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $420 × 9 = $3780

Thus, Simple Interest (SI) = $3780

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 Answer


Similar Questions

(1) Joseph took a loan of $5400 at the rate of 8% simple interest per annum. If he paid an amount of $7992 to clear the loan, then find the time period of the loan.

(2) John took a loan of $4400 at the rate of 6% simple interest per annum. If he paid an amount of $6512 to clear the loan, then find the time period of the loan.

(3) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 5% simple interest for 8 years.

(4) How much loan did Mark borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7360 to clear it?

(5) Find the amount to be paid if Charles borrowed a sum of $5900 at 4% simple interest for 7 years.

(6) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 10% simple interest?

(7) Robert took a loan of $4200 at the rate of 6% simple interest per annum. If he paid an amount of $5964 to clear the loan, then find the time period of the loan.

(8) Karen had to pay $4542.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) Mark took a loan of $6800 at the rate of 6% simple interest per annum. If he paid an amount of $9656 to clear the loan, then find the time period of the loan.

(10) David took a loan of $4800 at the rate of 10% simple interest per annum. If he paid an amount of $7680 to clear the loan, then find the time period of the loan.


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