I'm on this question too and all I know is store C is a better buy. I'm not very sure why but I'm pretty sure it is.
the sequence starts at 10 and increases by 7 each time, thefore a possible sequence identification is:

Therefore, the 100th term is:
Answer:
3.5 inches
Step-by-step explanation:
create a proportion:
inches / miles = inches / miles
let 'x' = distance in inches
<u>1/4</u> = <u> x </u>
18 252
18x = 252(1/4)
18x = 63
x = 63 / 18
x = 3.5