Order of Operations PuzzleDate: 09/22/2002 at 23:25:04 From: Laurel Subject: Order of operations puzzle What is _ + _ x _ - _ = 22? We're given the numbers 2, 3, 4, 8. Date: 09/24/2002 at 00:01:18 From: Doctor Ian Subject: Re: Order of operations puzzle Hi Laurel, You're going to do the multiplication first, so the possible multiplications are: 2*3 = 6 2*4 = 8 2*8 = 16 3*4 = 12 3*8 = 24 4*8 = 32 That means that the answer must be one of these: __ + 6 - ___ = 22 use 4, 8 __ + 8 - ___ = 22 use 3, 8 __ + 16 - ___ = 22 use 3, 4 __ + 12 - ___ = 22 use 2, 8 __ + 24 - ___ = 22 use 2, 4 __ + 32 - ___ = 22 use 2, 3 This is a pretty common problem-solving technique: You replace one hard problem with some easier ones. Can you take it from here? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ |
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