Answer:




Step-by-step explanation:
Given
close
fail to close


First, calculate the value of q
Using complement rule



So, we have:
and 
Solving (a): Fails to close on the 4th attempt
This means that he closes the first three attempts. The event is represented as: p p p q
So, we have:




Solving (b): He closes for the first time on the 3rd attempt
This means that he fails to close the first two attempts. The event is represented as: q q p
So, we have:




Solving (c): First he closes is his 2nd attempt
This means that he fails to close the first. The event is represented as: q p
So, we have:



Solving (d): The first he close is one of his 3 attempts
To do this, we make use of complement rule
The event that he does not close any of his first three attempts is: q q q
The probability is:


The opposite is that the first he closes is one of the first three
So, we have:
--- complement rule




First of all, lets consider that you made a litte mistake and you meant this problem.........
<span>"The combined average weight of an okapi and a llama is 450 kilograms. The average weight of 3 llamas is 190 kilograms more than the average weight of one okapi. On average, how much does an okapi weigh, and how much does a llama weigh?"
This is a system of two equations.
Let it be X the average weight of a LLAMA
And Y the average weight of an OKAPI
X + Y = 450 kg 1)
3X = 190 kg +Y 2)
So, with 1) we have that Y = 450 - X
We subsitute in 2) and we have
3X = 190 + (450 -X).............We solve for X ....==> 4X = 640kg ==> X = 160kg
..We replace X in 1 and get => Y = 450kg -X = 450kg -160kg = 290kg
</span>160kg....... average weight of a LLAMA
290kg........average weight of an OKAPI
Answer:
Step-by-step explanation:
9 * -9 * -1 =
-81 * -1 =
81 <===
In multiplying (or dividing), if the signs are the same, the result is positive
if the signs are different, the result is negative
these rules do not apply to addition or subtraction