Answer:
I don't know about 4 but of no. 6, it is A
Step-by-step explanation:
<u>Question 1 solution:</u>
You have two unknowns here:
Let the Water current speed = W
Let Rita's average speed = R
We are given <em>two </em>situations, where we can form <em>two equations</em>, and therefore solve for the <em>two unknowns, W, R</em>:
Part 1) W→ , R←(against current, upstream)
If Rita is paddling at 2mi/hr against the current, this means that the current is trying to slow her down. If you look at the direction of the water, it is "opposing" Rita, it is "opposite", therefore, our equation must have a negative sign for water<span>:
</span>R–W=2 - equation 1
Part 2) W→ , R<span>→</span>(with current)
Therefore, R+W=3 - equation 2
From equation 1, W=R-2,
Substitute into equation 2.
R+(R–2)=3
2R=5
R=5/2mi/hr
So when W=0 (still), R=5/2mi/hr
Finding the water speed using the same rearranging and substituting process:
1... R=2+W
2... (2+W)+W=3
2W=1
W=1/2mi/hr
Parallel graphs have the same slope. perpendicular has opposite reciprocal slopes. These equations have slopes of -2/5 and 25 so they are neither.
The number is less than 190,000 and greater than 180,000
5,000 more than the number has 187 thousands
2000 less than the number has 4 hundreds
180, 000 <n> 190, 000
180,000 + 2000 = n = 5000-187, 000
182,000 = n = 182, 000
Or,
180, 000 <n> 190,000
n + 5000= 187, 000 n – 2000 = 180, 000
n= 187, 000- 5000 n = 180, 000 + 2000
n= 182, 000 n= 182, 000
We're told that



where the last fact is due to the law of total probability:



so that
and
are complementary.
By definition of conditional probability, we have



We make use of the addition rule and complementary probabilities to rewrite this as


![\implies P(B)-[1-P(A\cup B)^C]=[1-P(B)]-P(A\cup B^C)](https://tex.z-dn.net/?f=%5Cimplies%20P%28B%29-%5B1-P%28A%5Ccup%20B%29%5EC%5D%3D%5B1-P%28B%29%5D-P%28A%5Ccup%20B%5EC%29)
![\implies2P(B)=2-[P(A\cup B)^C+P(A\cup B^C)]](https://tex.z-dn.net/?f=%5Cimplies2P%28B%29%3D2-%5BP%28A%5Ccup%20B%29%5EC%2BP%28A%5Ccup%20B%5EC%29%5D)
![\implies2P(B)=[1-P(A\cup B)^C]+[1-P(A\cup B^C)]](https://tex.z-dn.net/?f=%5Cimplies2P%28B%29%3D%5B1-P%28A%5Ccup%20B%29%5EC%5D%2B%5B1-P%28A%5Ccup%20B%5EC%29%5D)


By the law of total probability,


and substituting this into
gives
![2P(B)=P(A\cup B)+[P(B)-P(A\cap B)]](https://tex.z-dn.net/?f=2P%28B%29%3DP%28A%5Ccup%20B%29%2B%5BP%28B%29-P%28A%5Ccap%20B%29%5D)

