Don't let fractions fool you.

of a tank in

an hour is equal to:
1/12 of a tank in 20 minutes.
Thus we know in an hour, an oil company can fill 3/12 of a tank (60 minutes in an hour).
3 x 4 = 12, and 12/12 = 1(a whole tank), so we multiply 1 (hour) by 4.
Our answer is that it takes 4 hours to fill a tank.
Midday is 12pm so you add whatever hours to that. Which is 1:20pm after midday (12pm)
Answer:
The answer is 
Step-by-step explanation:
Assuming the snowball is a perfect sphere, then if A denotes the surface area and D the diameter then:

Differentiating wrt r we have:

We are told that
and we want to find 
By the chain rule we have:

∴
∴
When D=10 then

The sign (-) shows that the D is decreasing.
She is correct.
She starts with 50
Each square foot adds 3 dollars...
so Square feet can be represented by x, and cost will be y... giving this linear function:
y=3x+50.
Answer: 480 minutes
Step-by-step explanation: There's 60 minutes in 1 hour. Multiply the number of minutes in an hour times the number of hours. 8*60=480