Answer:
a) The probability of selling less than 100 gallons (x≤1) is P=0.16.
b) The mean number of gallons is M=80 gallons.
Step-by-step explanation:
The probability of selling x, in hundred of gallons, on any day during the summer is y(x)=0.32x, in a range for x from [0;2.5].
The probability of selling less than 100 gallons (x≤1) is then:

The mean number of gallons can be calculated as:

Green or purple = 10
prob(green or purple) = 10/30 = 1/3
We can find the length of the ladder by squaring the known digits, adding them, and finding the square root of the sum. This would mean our first equation, after squaring, will look like this:
49+81=130
Now that we have <em>c</em> squared, we can go through and find the approximate square root, which is 11.4. That would mean the ladder is 11.4 meters long.
Assuming the order does not matter, you want the number of combinations of 9 things taken 5 at a time. The combinations can be shown as C(9,5), 9C5.
C(9, 5) =
9/5(9-5) =
9*8*7*6*5 / 5*4
The 5 terms cancel.
9*8*7*6 / 4*3*2 =
9*7*2 =
126
The above change is because 4*2 cancels the 8 in the numerator and 6/3 = 2
Therefore, the solution is 126.