Hey buddy I am here to help!
Red = 8
blue = 6
greem = 4
total = 18
probability of blue marble = 6/18 = 1/3
Answer: 
Step-by-step explanation:
Given: A tourist first walked 17km with a speed of v km/h.
Since 
therefore, 
Let
be the time he walked with speed v.
then 
Also he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed.
Let
be the time he hiked 12 km,
Then 
The total time for the whole trip is given by:-

Substitute the values of
and
in the equation, we get

You would need 3 pails of plaster, specifically about 2 pails and a fifth of another but you cant buy a fraction of a pail, so 3 pails are needed.