Question

A sandwich store charges a delivery fee to bring lunch to an office building. One office pays $33 for 4 turkey sandwiches. Another office pays $61 for 8 turkey sandwiches. How much does each turkey sandwich add to the cost of the delivery fee? Explain how you know

Answer 1

$12

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