#1A fair coin is flipped 30 times. What is the probability the coin will show heads less than 17 times?

My work: 1 P(NOT 17) = 1 - (30C13)(.5)^30

Answer:0.7077

#2Tom has a 1/2 of shooting the target, and Kate has a 1/3 chance of shooting the target. What is the probability that atleast one of them will shoot the target? What is the probability that both of them will shoot the target? (This is independent)

Answer: ?

#3A rock concert is attended by 1300 students of whom 760 are girls and 540 are boys. If 4 of these students are randomly chosen to receive backstage passes, what is the probability that at most 3 of the chosen will be boys?

My work:

1 - P(OB, 3G)

1-(1300C3)(760/1300)^3

Answer:0.9704