The train traveled 60 miles per hour since 360 miles divided by 6 hours gives you 60 mph
Liters is the best. A bathtub can hold a lot of water.
To simplify fractions, all you have to do is divide both the numerator and the denominator by the greatest common factor of both integers.
In this case, the greatest common factor of 2 and 10 is 2.
2/2=1
10/2=5
So, 2/10 in its simplest form is 1/5.
ANSWER
D.

EXPLANATION
The given graph rises on the left and falls on the right.
This implies that the degree of the function is even.
Since the graph opens downward, the coefficient of the leading term must be negative.
The graph graph of the function also has 3 intercepts with one of them having an even multiplicity.
This means that the degree must be 4.
Therefore the last choice is correct.