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Math II-A 2.25

 
 
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Re: Math II-A 2.25
by Eric Duan - Sunday, December 13, 2020, 7:42 PM
 

I figured it out:

Rectangulars: 7C2 x 6C2=315

Squares: side=1+side=2+side=3+side=4+side=5

                    6x5+5x4+4x3+3x2+2x1=70

315-70=245