Answer:
$12
Step-by-step explanation:
assuming that the cost of delivery is constant irrespective of the number ordered
Let the cost of sandwich be x
First office
$33=4x+c where c is the cost of delivery
Second office
$61=8x+c
These two are simultaneous equation. Subtracting the equation of first office from the second office we obtain
4x=28
Therefore, x=28/4=7
The cost of delivery is 33-(4*7)=33-28=5
Therefore, one sandwich plus delivery costs 7+5=$12
