Answer :
B. 6(3×10+4×12)
Aaron baked 30 a day
Plus Ethan's 60 a day
For 6 days straight
6(30+60)
6(90)
540 cookies total
Aaron baked 30 a day
Plus Ethan's 60 a day
For 6 days straight
6(30+60)
6(90)
540 cookies total