Help me wit this thank you

An airport in death valley is 60 feet below sea level, and an airplane is flying 2,000 feet above sea level. how many feet must the plane descend in order to land? a. 2060 b. 2000 feet c. 1940 feet d. 1880 feet e.1400 feet will mark as brainliest

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Consider an example of a deck of 52 cards: example set of 52 playing cards: 13 of each suit clubs, diamonds, hearts, and spades ace 2 3 4 5 6 7 8 9 10 jack queen king clubs diamonds hearts spades 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.