Difference between revisions of "2015 AIME I Problems/Problem 1"

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The expressions <math>A</math> = <math> 1 \times 2 + 3 \times 4 + 5 \times 6 + *** + 37 \times 38 + 39 </math> and <math>B</math> = <math> 1 + 2 \times 3 + 4 \times 5 + *** + 36 \times 37 + 38 \times 39 </math> are obtained by writing multiplication and addition operators in an alternating pattern between successive integers.  Find the positive difference between integers <math>A</math> and <math>B</math>.
 
The expressions <math>A</math> = <math> 1 \times 2 + 3 \times 4 + 5 \times 6 + *** + 37 \times 38 + 39 </math> and <math>B</math> = <math> 1 + 2 \times 3 + 4 \times 5 + *** + 36 \times 37 + 38 \times 39 </math> are obtained by writing multiplication and addition operators in an alternating pattern between successive integers.  Find the positive difference between integers <math>A</math> and <math>B</math>.
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== See also ==
 
== See also ==
 
{{AIME box|year=2015|n=I|before=First Problem|num-a=2}}
 
{{AIME box|year=2015|n=I|before=First Problem|num-a=2}}
 
{{MAA Notice}}
 
{{MAA Notice}}
 
[[Category:Introductory Geometry Problems]]
 
[[Category:Introductory Geometry Problems]]

Revision as of 15:50, 20 March 2015

Problem

The expressions $A$ = $1 \times 2 + 3 \times 4 + 5 \times 6 + *** + 37 \times 38 + 39$ and $B$ = $1 + 2 \times 3 + 4 \times 5 + *** + 36 \times 37 + 38 \times 39$ are obtained by writing multiplication and addition operators in an alternating pattern between successive integers. Find the positive difference between integers $A$ and $B$.

See also

2015 AIME I (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
All AIME Problems and Solutions

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