What’s the measurement of 2? please help

What is the probability of drawing three queens from a standard deck of cards, given that the first card drawn was a queen? assume that the cards are not replaced.

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms

What is the solution to the system of equation graphed belowa.(0,-4)b.(2,5),1),-3)