Fun, geometry disguised as probability.
That's a pentagon, which we can view as 10 right triangles with legs a and s/2 (half of s) and hypotenuse r. So area of the pentagon is
P = 10 × (1/2) a (s/2) = 10 (1/2) (3.2) (4.7/2) = 37.6
The area of the circle is πr² so the circle area is
C = π (4²) = 50.265482
The white area is the difference, C-P, and the probability we seek is the fraction of the circle that's white, so (C-P)/C.
p = (C-P)/C =1-P/C = 1-37.6/50.265482 = 0.251971
Answer: 0.25
Higher than I would have guessed from the figure.
<u>ANSWER</u>
It is not one-to-one function
<u>EXPLANATION</u>
A one-to-one function must pass the horizontal line test.
The graph described in the question looks like the one in the attachment.
A horizontal line drawn in red cuts the graph at more than one point.
Therefore the parabola shown facing up with a vertex 
is not a one-to-one function.
3/4+2/6+1/2 = 9/12+4/12+6/12 = 19/12 Brendan has 1 7/12 leftover pizzas. THis is achieved by multiplying for a common denominator and adding
19/12-2/3 = 19/12-8/12 = 11/12 Brendan has 11/12 more pizzas than Steve.
Red to total I believe is 12/23
