Answer:
Widgets should be sold by $38.88 to maximize the profit.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:
It's vertex is the point 
In which
Where
If a<0, the vertex is a maximum point, that is, the maximum value happens at 
, and it's value is 
.
In this question:
The profit is given by:
Which is a quadratic function with 
The maximum profit happens at the x of the vertex. Thus
Widgets should be sold by $38.88 to maximize the profit.
If you are making 4 billion a second do 4,000,000,000 x 60 = 240,000,000,000
Then times that by 10 which equals. 2,400,000,000,000
Is the answer for the second one
6,000,000,000 x 60 x 60 x 2 = 1,296,000,000,000,000
I think the answer is 4:24
Around 6 hours (exact decimal would be 5.99865). I did this by multiplying 14.85*40 (getting 594). After that, I subtracted 594 from 727.65 (getting 133.65), then multiplying 14.85 by 1.5, getting 22.28, and then, I did 133.65/22.28, getting 5.99865, which I rounded to 6.
