I think the answer is 263.52. Hope it's right!
Yes, because you can simplify it to .2 which can be written as a fraction. Irrational numbers are those ones that keep going with an infinite string of numbers past the decimal.
A and B are dependent events.
The general probabilities of each event to happen separately is 36% for event A and 25% for event B. When considering that Chris passes one before passing the other, indicates that whether he gets the first light open or not will affect if he gets the other one also open or not. This can even be seen by noticing how the probability of Chris getting both red lights is 9%, a much inferior probability then considering both lights separately which means that one event has influence over the other.
X+(4x-20)=180
=>5x-20=180
=>5x=200
=>x=40
You can't make a triangle with those lengths for sides.
The way I look at it is like this:
-- Take 2 sticks ... lengths 4 and 2 ... and connect them together at one end.
-- The farthest they can reach, if they're opened up completely and pointing
in opposite directions, is a distance of 6 .
-- They can't reach the ends of a stick that is 7 long. So you can't make
a triangle with those 3 sticks.