Examples of this are:
2 and 
2 and 
4 and 
I'm guessing you have a work sheet going along with this which has actual images of containers. I've attached an example - if you can post the actual work sheet you're referring to I can edit this answer to correctly reflect your specific question.
Answer:
145
Step-by-step explanation:
The answer to your question is 4x-12
About miles.
Subtract the flat rate of 1.75 from the spending limit of 10$ which leaves you with 8.25 then divide the rest of your spending money (8.25$) into your rate per mile (0.65) , so essentially , 8.25 / 0.65 which leaves you with the answer of ;
12 miles.