If he baked 2 dozens or 2*12=24 cookies in 23 minutes, in how much time will he bake 12 dozen 0r 12*12=144 cookies? If 2dozen=23 min 12 dozen=? 12/2*23=6*23=138 mins or 2 hours 18 minutes Therefore he can bake 12 dozens or 144 cookies in 138 minutes or 2 hours 18 minutes