What? what is the question?
Tripod will not tip over because: a plane contains at least 3 noncollinear points .
Answer: B )
The second one is the answer: f(4) = 22
How many different combinations of “on” and “off” are possible with 8 “light bulbs”?
Answer: The total number of combinations of "on" and "off" that are possible with 8 "light bulbs" is 
Therefore, 256 different combinations of “on” and “off” are possible with 8 “light bulbs”
Answer:
B. 199
Step-by-step explanation:
We are given an Arithmetic sequence : 3, 7, 11, 15, ...
We are supposed to find the 50th term .
So, first consider the formula of nth term in Arithmetic mean:

where
a is first term of sequence
n is term position
d is common difference
= the term you are supposed to find
Now,
a = 3 ( first term )
n = 50 th term ( given )
d = 7-3 = 11-7 = 4(common difference
Substitute these value in the formula given above
⇒
⇒
⇒
⇒
Hence ,The 50th term of given arithmetic sequence is 199
So, OPTION B is correct .