Iwill give 10-20 ! need ! what is the mean of variable a?

Astandard deck of cards contains 52 cards. one card is selected from the deck. (a) compute the probability of randomly selecting a seven or king. (b) compute the probability of randomly selecting a seven or king or jack. (c) compute the probability of randomly selecting a queen or spade.

Janet is rolling a number cube with the numbers one through six she record the numbers after each row if she rolls of keep 48 times how many times should she expect to roll a 4

Two airplanes start at the same place and travel in opposite directions, one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?