Answer:
20 Bicycles
Step-by-step explanation:
The function for the average cost,C(x) [in hundred of dollars] per bicycle whenever x hundred bicycles are built is given as:

The minimum value of C occurs at the axis of symmetry.
Axis of Symmetry, 
Comparing with the standard form of a quadratic equation 
a=0.5, b=-0.2

x=0.2 Hundreds =0.2 X 100 =20
When Aki's Bicycle Designs produces 20 Bicycles, the cost is minimized.
Answer:
Required equation : 
Together they can paint the same room in 2.25 hours or 2 hours 15 minutes.
Step-by-step explanation:
It is given that Dale Horton can paint a certain room in 3 hours.
One hour woks of Dale Horton = 1/3
Kathy Garcia can paint the same room in 9 hours.
One hour woks of Kathy Garcia = 1/9
Let together they can paint the same room in t hours.
One hour woks of both = 1/t



After reciprocal we get


1 hour = 60 minutes.
0.25 hour = 15 minutes.
Therefore, together they can paint the same room in 2.25 hours or 2 hours 15 minutes.