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)


Answer:
10 pages
Step-by-step explanation:
1 and 1/3 pages multiplies by 7.5 brings us to the answer of ten pages
20 minutes goes into 2 and 1/2 hours 7.5 times
Answer:
the slope of the line is 2/3x
Step-by-step explanation:
i hope this helps :)
It's easy once you spot the ones that can cross cancel!
Say we have the fractions 8/10 and 20/23.
(it's easier to see on top of each other)
If you look diagonally , so 8 and 23 and 10 and 20, you can see that 10 and 20 have a common factor. So we divide it by the highest common factor to reduce those numbers, making it easier to multiply. 10 and 20 can become 1 and 2, dividing by 10. So now we are left with 8/1 and 2/23, and now we multiply normally going across so 16/23.
This works going both diagonals and simplifying both, but in that case it would be easier to try and simplify the fractions before cross multiplying them.
Basically: look for those diagonals and if they can be divided down by the highest common factor, go for it to make it easier to multiply normally afterwards.
Hope I helped!