Meena bakes a total of 5 x 12 = <<5*12=60>>60 cookies.
Mr. Stone buys 2 x 12 = <<2*12=24>>24 cookies.
Brock buys 7 cookies, so Katy buys 2 x 7 = <<7*2=14>>14 cookies.
Meena sells a total of 24 + 7 + 14 = <<24+7+14=45>>45 cookies.
She has 60 - 45 = <<60-45=15>>15 cookies left.
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