Chapter 6: Problem 25
It takes 1.5 hours less time for a Cisco Systems server to send out a set of email advertisements than it takes a Dell PowerEdge server to send out the same emails. Working together, the servers can complete the emailing in 1.8 hours. How long would it take each server, working alone, to complete the job?
Short Answer
Step by step solution
Define the Variables
Express Each Server's Rate
Set Up the Combined Rate Equation
Solve the Equation for x
Solve the Quadratic Equation
Find Cisco Server's Time
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Quadratic Equations
Solving a quadratic equation like \( ax^2 + bx + c = 0 \) requires techniques such as factoring, completing the square, or using the quadratic formula. In our exercise, the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \) was utilized to solve \( x^2 - 5.1x + 2.7 = 0 \). Let's break it down:
- Identify \( a = 1 \), \( b = -5.1 \), and \( c = 2.7 \).
- Calculate the discriminant \( b^2 - 4ac = 15.21 \).
- Find the square root of the discriminant, yielding the roots: \( x = \frac{5.1 \pm 3.9}{2} \).
- The feasible solution is \( x = 4.5 \) because it must be greater than the time difference (1.5 hours).
Combined Work Rate
The combined work rate equation is formed by summing the individual work rates of those involved. This is expressed as \( \frac{1}{x} + \frac{1}{x-1.5} = \frac{1}{1.8} \), where:
- \( \frac{1}{x} \) is Dell's work rate.
- \( \frac{1}{x-1.5} \) is Cisco's work rate.
- The sum of these rates needs to equal the reciprocal of their combined time, which is 1.8 hours.
Algebraic Equations
In this exercise, the algebraic equation \( \frac{(x-1.5) + x}{x(x-1.5)} = \frac{1}{1.8} \) combined the rates of the two servers to model their collaborative effort. Solving such equations typically involves:
- Finding a common denominator to simplify fractions.
- Cross-multiplying to eliminate fractions.
- Rearranging terms to form a standard or recognizable equation, such as a quadratic form.