D.8
A and C are out because they would get you ether lower or equal to 20, which is equal to AC and your trying to find X in AB which is so posed to be the what equals AC+BC.
AB=AC+BC
5x=20+BC
5(8)=20+BC
40=20+BC
40=20+20
AC equals 20. AB will have to equal AC+ CB. If you put in A.4 in AB 5X you will get twenty and that not what you want. You want to get a number that will get you the an answer greater to AC. So 5(8)=40.
Answer:
with what know question was there
Answer:
17.5%
Step-by-step explanation:
First of all, see this situation as a cumulative binomial distribution. You have isolated trials with a probability of success. This makes it binomial. The wording of the question "what is the probability of at least half..." makes this cumulative.
There are a few ways to calculate this, and I'm not quite sure which way you're familiar with. I'll show the cumbersome way and use wolfram to make the calculation.
First, I'll calculate the probability for 15 success, given 30 trials.
30c15*0.4^15*0.6^15
Since the question asks for the probability of at least 15 success, I'll have to make a calculation for the probability of 16 successes, then 17, and so on. Then I'll have to add all the probabilities together. So, I'll use wolfram for that (see attached)
Answer:
15) ∠BCD = 1/2 short arc BC = (360° -260°)/2 = 50° (C)
16) ∠K is supplementary to short arc JL = 180° -120° = 60° (C)
17) ∠V is half the difference of long arc TW and short arc UW.
.. (198° - UW)/2 = 69°
.. 198° -138° = UW = 60° (C)
18) ∠L is supplementary to short arc KM
.. KM = 180° -66° = 114° (C)
Step-by-step explanation: hope it helped