Looks like the PMF is supposed to be

which is kinda weird, but it's not entirely clear what you meant...
Anyway, assuming the PMF above, for this to be a valid PMF, we need the probabilities of all events to sum to 1:

Next,





If

, then

, where we take the positive root because we know

can only take on positive values, namely 1, 2, and 5. Correspondingly, we know that

can take on the values

,

, and

. At these values of

, we would have the same probability as we did for the respective value of

. That is,

Part (5) is incomplete, so I'll stop here.
Answer:
D m = 
Step-by-step explanation:
factor the expressions in the denominator and the numerator to simplify the expression:
=> 
=> 
to make a fraction undefined, the numerator should be 0, thus, we substitute the values of m from the options into the denominator to make the denominator equals to 0:
=>
=
= 
in this case, the values of m from option D make the denominator of the fraction equals 0.
Answer:
11 hours and 15 minutes (11.25)
Step-by-step explanation:
make a ratio
160:4.5
240/160=1.5
so 1 and 1/2 intervals of 4.5 hours
4.5+4.5= 9
4.5/2=2.25
9+2.25=11.25
The area of the square is 100ft