Show that this are equal​

Three coins are flipped. what is the probability that there will be at least two tails?

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

Which inequality comparing two of the expressions is true when 0.7 < x < 0.9