http://homework.cpm.org/cpm-homework/resources/CPM/CC/CC3/Ch3/3-88/ca8dae7834681ca2bd0e036902407796/AC_2_116_c.png

the answer to this is:

Miles      Gallons

280           14

140            7

420          21

20            1

100          5

1000        50

350       17.5

hope this helps