Benny will spend 3 * 10 = $<<3*10=30>>30 to make the pumpkin pies.
He will spend 5 * 12 = $<<5*12=60>>60 to make the cherry pies.
He wants to make a profit of $20, so he has to earn 30 + 60 + 20 = $<<30+60+20=110>>110 selling all the pies.
He is making 22 pies, so he needs to charge 110 / 22 = $<<110/22=5>>5 per pie.
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