How to calculate damage?

Question

Say a a machop with 40 attack uses stone edge on a bidoof with 28 defense how much damage would it be

Answer 1

You forgot to include what level they.
but assuming they are both level 100 it would be
Min:103 Avg:112 Max:122

Lvl 10(both)
Min:16 Avg:17 Max:19

Lvl 15(both)
Min:20 Avg:22 Max:24

Machop(20) Bidoof(15)
Min:25 Avg:27 Max:30

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http://www.psypokes.com/dex/damage.php