Answer:
A & B
Step-by-step explanation:
It might be k, since 4-4 is 0 and 0 has no absolute value.
The reason why the bulletin board notice feel nervous is: it was under a tack
In most common cases, the notice that is putted under a tack is intended to be displayed on the board for a pretty long time, highlighting the importance and the urgeny of the notice.
P(<100) = P((new or change) & <100) = P(new & <100) + P(change & <100)
... = P(<100 | new)*P(new) + P(<100 | change)*P(change)
... = 0.90*0.70 + 0.20*0.30
... = 0.63 + 0.06 = 0.69 . . . . probability of completing a transaction in < 100 ms
