Answer:
Ques 16)
We have to simplify the expression:

Ques 17)

Ques 18)
Let the blank space be denoted by the quantity 'x'.

Ques 19)
Let the missing quantity be denoted by 'x'.

Since we don't know the length of the trip, we can't find an exact answer.
However, we can write an expression for it. First, we let, T, represent the total number of miles for the trip.
Now, just divide T by 33. So our expression is T/33.
If you know the total miles of the trip, just divide it by 33 and you will have the answer.
400/160=2.5 This is finding the necessary multiplier
2.5*5=x I used 2.5 and multiplied it by 5
x=12.5 minutes This is the answer
It would take 12 minutes and 30 seconds
Since the outside is 1.5 to 1, we take half of the value of the inside diameter and add it to itself to get the smallest value needed. 0.5+0.25=0.75
So the smallest diameter possible would be 0.75 inches.