hi
-16t²+250 = 75
-16t² = 75 -250
-16t² = -175
t² = -175 /-16
t² = 175/16
Here there si two solutions : t =
and t = - 
However, as time cannot rewind, we will keep only positive solution
So t = 
in seconds it will be : 3.3 seconds
Answer: B
Step-by-step explanation:
LJ should corresponds with RQ but it should correspond with PR.
I think it would be y=(-9/5)x -1/9
Answer:
c) it appears to be sound because the data are not biased in anyway.
Step-by-step explanation:
From the information given regarding the sample selection method , the size, the larger sample from which the survey subject were selected, we can conclude that the data is sound and not in anyway biased. The subject were selected from a reputable market research firm, which means the subjects were chosen from a larger sample which is reliable and not just a voluntary pool of subjects. Also, the selection process is randomized. Based on these, there are no flaws which are likely to cause the introduction of bias into the sample selected. Hence, the data is sound and not in any way biased.
Estimation:
23 --> rounded to 20
71 --> rounded to 70
70 + 20 = 90. I rounded both numbers down so the exact sum must be only a little greater than my estimate.