Please help me answer this question:

Total area = 141,

the trapezoid = 117, the triangle=24

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