Simple Interest
Math MCQs

Question :    What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 3% simple interest?

Correct Answer  $3953

Solution & Explanation

Solution

Given,

Principal (P) = $3350

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $3350 × 3% × 6

= $3350 ׳/₁₀₀ × 6

= ^{3350 × 3 × 6}/₁₀₀

= ^{10050 × 6}/₁₀₀

= ⁶⁰³⁰⁰/₁₀₀

= $603

Thus, Simple Interest = $603

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 = $3350 + $603

= $3953

Thus, Amount to be paid = $3953 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 = $3350

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3350 + ($3350 × 3% × 6)

= $3350 + ($3350 ׳/₁₀₀ × 6)

= $3350 + (^{3350 × 3 × 6}/₁₀₀)

= $3350 + (^{10050 × 6}/₁₀₀)

= $3350 + (⁶⁰³⁰⁰/₁₀₀)

= $3350 + $603 = $3953

Thus, Amount (A) to be paid = $3953 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $3350, the simple interest in 1 year

= ³/₁₀₀ × 3350

= ^{3 × 3350}/₁₀₀

= ¹⁰⁰⁵⁰/₁₀₀ = $100.5

Thus, simple interest for 1 year = $100.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $100.5 × 6 = $603

Thus, Simple Interest (SI) = $603

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3350 + $603

= $3953

Thus, Amount to be paid = $3953 Answer

Similar Questions

(1) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $7644 to clear the loan, then find the time period of the loan.

(2) How much loan did Ronald borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8625 to clear it?

(3) What amount does Elizabeth have to pay after 6 years if he takes a loan of $3450 at 9% simple interest?

(4) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 6% simple interest?

(5) James took a loan of $4000 at the rate of 9% simple interest per annum. If he paid an amount of $7600 to clear the loan, then find the time period of the loan.

(6) What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 7% simple interest?

(7) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 7% simple interest.

(8) Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 10% simple interest.

(9) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $8008 to clear the loan, then find the time period of the loan.

(10) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 3% simple interest?