Answer: 14 miles ≤ D ≤ 22 miles.
Step-by-step explanation:
The mean distance traveled per gallon, is 18 miles.
But this can fluctuate, at most, by 4 miles.
Because we have here the "at most", we know that we should use the ≤, ≥ symbols.
Then, if the mean is 18mi, the range of possible distances traveled per gallon is:
(18 miles - 4 miles) ≤ D ≤ (18 miles + 4 miles)
Where D is the distance.
14 miles ≤ D ≤ 22 miles.
So the truck can get between 14 miles and 22 miles per gallon on the highway.
Answer:
8%
Step-by-step explanation:
The maximum change happens when all 500 people moves form outer surface to the station center. When all of them are at the surface, the total moment of inertia is:

When they are at the axis, the total moment of inertia is only the station's, which is 
By the law of angular momentum conservation:


So the angular speed changes by 0.08 of itself, or 8%
The rachos were sold are 6
because ratio of them at the begining = 3/4
after selling some popcorns, ratio of them still 3/4
they sold 8 popcorns mean 3/4 = ?rachos / 8popcorns sold
the rachos sold = 3*8/4 = 6