PRACTICAL PROBLEMS in MATHEMATICS for HEATING AND COOLING TECHNICIANS Fifth Edition Russell DeVore Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States Practical Problems in Mathematics for Heating and Cooling Technicians, Fifth Edition Russell DeVore Vice President, Career and Professional Editorial: Dave Garza Director of Learning Solutions: Sandy Clark Senior Acquisitions Editor: James Devoe Managing Editor: Larry Main Product Manager: John Fisher Editorial Assistant: Thomas Best Vice President, Career and Professional Marketing: Jennifer McAvey © 2009 Delmar, Cengage Learning ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher. For product information and technology assistance, contact us at Professional & Career Group Customer Support, 1-800-648-7450 For permission to use material from this text or product, submit all requests online at cengage.com/permissions Further permissions questions can be e-mailed to
[email protected] Marketing Director: Deborah S. Yarnell Marketing Manager: Jimmy Stephens Marketing Coordinator: Mark Pierro Production Director: Wendy Troeger Production Manager: Mark Bernard Library of Congress Control Number: 2008926960 ISBN-13: 978-1-4283-2428-2 ISBN-10: 1-4283-2428-3 Content Project Manager: David Plagenza Art Director: Benj Gleeksman Technology Project Manager: Christopher Catalina Production Technology Analyst: Thomas Stover Delmar 5 Maxwell Drive Clifton Park, NY 12065-2919 USA Cengage Learning products are represented in Canada by Nelson Education, Ltd. For your lifelong learning solutions, visit delmar.cengage.com Visit our corporate website at cengage.com Notice to the Reader Publisher does not warrant or guarantee any of the products described herein or perform any independent analysis in connection with any of the product information contained herein. Publisher does not assume, and expressly disclaims, any obligation to obtain and include information other than that provided to it by the manufacturer. The reader is expressly warned to consider and adopt all safety precautions that might be indicated by the activities described herein and to avoid all potential hazards. By following the instructions contained herein, the reader willingly assumes all risks in connection with su