Answer:
275 miles
Step-by-step explanation:
Let x be the number of miles Alan has to drive to get the same cost for tha two plans.
1 plan: total cost

2 plan: total cost

Equate them:

If you have a fraction, take one number and put a different number on top or underneath, for example if you have 2 cats and 3 dogs, the ratio from cats to dogs would be 2:3 but if you did 2 cats to the total number of animals, you would add 2 and 3 and get 5, so the ratio would be 2:5.
Answer: The volume of largest rectangular box is 4.5 units.
Step-by-step explanation:
Since we have given that
Volume = 
with subject to 
So, let 
So, Volume becomes,

Partially derivative wrt x and y we get that

By solving these two equations, we get that

So, 
So, Volume of largest rectangular box would be

Hence, the volume of largest rectangular box is 4.5 units.