Answer:
25% probability that all three residents will choose the same plumbe
Step-by-step explanation:
For each resident, there are only two possible outcomes. Either they choose the first plumbe, or they choose the second. The plumbers are chosen independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
Each resident randomly chooses one of the two plumbers.
This means that 
Three residents:
This means that 
What is the probability that all three residents will choose the same plumb
This is P(X = 0)(all choose the second pumble) or P(X = 3)(all choose the first pumble). So

25% probability that all three residents will choose the same plumbe
Time taken by Ria to paint a room = 4 hours
Time taken by Destiny to paint a room = 6 hours
If they work together, they complete 1 job. So,

The LCD of 4 and 6 is 12




Hence, both of them can paint the room in
hours or 2.4 hours.
Answer:
<h2><em>The percent decrease is approximately 40%. </em></h2>
Step-by-step explanation:
Step one:
given data
initial count of fish= 850
final count of fish= 500
Required
% decrease
Step two:
% decrease= final-initial/initial*100
substitute
% decrease= 850-500/850*100
% decrease=350/850*100
% decrease= 0.41*100
% decrease= 40.1%
<em>The percent decrease is approximately 40%. </em>
Y = a (x + 3)² - 1
Let's take the point (-1;3)
3 = a ( -1 + 3)² - 1
3 = 4a - 1
4a = 4
Therefore a = 4/4 = 1
(x+3)² - 1
= x² + 6x + 9 - 1
= x² + 6x + 8
The answer would be y = x² + 6x + 8.
Hope this helps !
Photon