Answer:
C. 3.33 hours
Step-by-step explanation:
Use the algebra work equation:
=
+
, where tb is the time to work together, t1 is the time it takes one person, and t2 is the time it takes the other person
Plug in the values we know:
=
+ 
=
+ 
= 
20 = 6tb
3.33 = tb
So, it would take them 3.33 hours when working together.
Answer:
(see image)
bottom right image
Explanation:
First try the origin (0,0) to rule out two of the graphs.
3y ≥ x - 9 3(0) ≥ (0) - 9
3 ≥ - 9
yes 3x + y > - 3 3(0) + (0) > - 3
3 > - 3
yes so the origin should be in the shaded area of the graph, which rules out the top right and bottom left graphs.
Now try a coordinate that is in the shaded area of one of the remaining graphs, but not in the other one. If it works, the graph is the one that has that point in the shaded region, and vice versa.
Try point (4, 2)
3y ≥ x - 9
3(2) ≥ (4) - 9
6 ≥ - 5
yes3x + y > - 3
3(4) + (2) > - 3
12 + 2 > - 3
14 > - 3
yesSo the graph is the bottom right one since (4, 2) is included in that shaded region.
The answer would be letter B. You can see that the price of the demanded products as the time passes by decreases. So the answer is letter B.
<span>C(15,9) * (1/2)^9 * (1/2)^6 = 5005/32768 = .153 approx</span>