Answer: total cost earn=$1360
adult sold =45
student sold =80
adult cost twice as student cost so we can say adult sold 45+45=90
so total sold=90+80=170
to get the cost of 1 meal we divide 1360 by 170
1360/170=8
one student meal cost=8$
one adult meal cost=8*2=16
total students meal cost=8*80=640$
total adult meal cost=16*45=720
640+720=1360