Price Plus 1/2 Price
Date: 12/05/2001 at 21:20:41 From: Michelle Subject: Math problems - critical thinking A puzzle book costs 5.00 plus one-half of its price. How much does the puzzle book cost? (It is not $7.50.)
Date: 12/05/2001 at 22:06:19 From: Doctor Ian Subject: Re: Math problems - critical thinking Hi Michelle, This is one of those cases where variables come in really handy. We're looking for a price. We don't know what it is, but we can give it a name: P. The price of the book is $5 plus one-half the price. \___________________/ \________________/ P = 5 + (1/2)*P Can you take it from here? (Note that, as if often the case in puzzles like this, there is a way to 'see' the answer without doing any computations at all. If the book costs $5 plus 1/2 its cost... then $5 must be the _other_ half of its cost.) - Doctor Ian, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.