Simple Interest
MCQs Math


Question:     What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 10% simple interest?


Correct Answer  $6080

Solution And Explanation

Solution

Given,

Principal (P) = $3800

Rate of Simple Interest (SI) = 10%

Time (t) = 6 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) = $3800 × 10% × 6

= $3800 ×10/100 × 6

= 3800 × 10 × 6/100

= 38000 × 6/100

= 228000/100

= $2280

Thus, Simple Interest = $2280

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 = $3800 + $2280

= $6080

Thus, Amount to be paid = $6080 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 = $3800

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

And, Time (t) = 6 years

Thus, Amount (A)

= $3800 + ($3800 × 10% × 6)

= $3800 + ($3800 ×10/100 × 6)

= $3800 + (3800 × 10 × 6/100)

= $3800 + (38000 × 6/100)

= $3800 + (228000/100)

= $3800 + $2280 = $6080

Thus, Amount (A) to be paid = $6080 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 $3800, the simple interest in 1 year

= 10/100 × 3800

= 10 × 3800/100

= 38000/100 = $380

Thus, simple interest for 1 year = $380

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $380 × 6 = $2280

Thus, Simple Interest (SI) = $2280

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $2280

= $6080

Thus, Amount to be paid = $6080 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 9% simple interest.

(2) How much loan did Kimberly borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7647.5 to clear it?

(3) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 4% simple interest.

(4) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 5% simple interest for 4 years.

(5) Find the amount to be paid if Joseph borrowed a sum of $5700 at 6% simple interest for 7 years.

(6) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 6% simple interest?

(7) Find the amount to be paid if Jessica borrowed a sum of $5750 at 7% simple interest for 7 years.

(8) Daniel took a loan of $6200 at the rate of 7% simple interest per annum. If he paid an amount of $10540 to clear the loan, then find the time period of the loan.

(9) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $12160 to clear the loan, then find the time period of the loan.

(10) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $7052 to clear the loan, then find the time period of the loan.


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