Answer:
Less than 13 pounds of grapes,
as 14 pounds of grape exceeds $35.80,
If you order as low as zero pounds of grapes, then the price of apple pounds would be $35.80/20 =$1.79 per pound
Step-by-step explanation:
Let
Quantity of Apple and grapes=20
Cost of apple=$2.19
Cost of grape=$2.60
Total cost of apple and grape=$35.80
a+g=20
a=20-g
PaQa+PgQg=35.80
2.19(20-g)+2.60g=35.80
43.8-2.19g+2.60g=35.80
0.41g=35.80-43.8
0.41g=-8
g=-8/0.41
g= -19.51
PaQa+PgQg=35.80
2.19a+2.60(-19.51)=35.80
2.19a-50.726=35.80
2.19a=35.80+50.726
2.19a=86.526
a=86.526/2.19
=39.51
PaA+PgG=35.80
Pa(20-G)+2.60G=35.80
35.80/2.60 = 13.77 pounds of grapes, but no money will be left to buy apples, unless Pa=0
G<13.77