P(A) means "Probability of Event A" The complement is shown by a little mark after the letter such as A' (or sometimes Ac or A): P(A') means "Probability of the complement of Event A" The two probabilities always add to 1.
Answer:
Step-by-step explanation

⇒ 80 + ( 2 * 0.01 ) + ( 9 * 0.001 )
⇒ 80 + 0.02 + 0.009
= 80.029
Answer:
the atoms can have different numbers of valence electrons
Answer: the answer is 164025
Step-by-step explanation:
B is the final and complete answer