Let's look at work rates per minute.
Together they can paint the wall in x minutes.
Working together, in 1 minute, they do 1/x of the job.
The student who paints the wall in 16 minutes does 1/16 of the job in 1 minute.
The student who paints the wall in 24 minutes does 1/24 of the job in 1 minute.
Together, they do 1/16 + 1/24 of the job in 1 minute, but from above, we see that together, they do 1/x of the job in 1 minute, so 1/16 + 1/24 must equal 1/x. That gives us our equation.
1/16 + 1/24 = 1/x
1/16 * 3/3 + 1/24 * 2/2 = 1/x
3/48 + 2/48 = 1/x
5/48 = 1/x
x = 48/5 = 9.6
Answer: It takes them 9.6 minutes, or about 10 minutes to do the job together.
Answer:
d)X=4 or x=-2
Step-by-step explanation:
X²-2x=8
X²-2x-8=0
(x-4)(x+2)=0
X-4=0 or x+2=0
X=4 or x=-2
Answer:
c. Asking people leaving a local election to take part in an exit poll
Step-by-step explanation:
Asking people leaving a local election to take part in an exit poll best represents the highest potential for nonresponse bias in a sampling strategy because of the importance of the local election compared to the exit polls.
It is worthy of note that nonresponse bias occurs when some respondents included in the sample do not respond to the survey. The major difference here is that the error comes from an absence of respondents not the collection of erroneous data. ...
Oftentimes, this form of bias is created by refusals to participate for one reason or another or the inability to reach some respondents.
-8/5
Rise over run aka how many it goes up/down over how many it goes across
