Need help with this!

answer is

b.

1.67

hope you get this right.

in counting the number of heads in 4 coin flips, the probability that we get exactly one head is the probability that we get anyone of the following 4 outcomes: httt, thtt, ttht, or ttth. each has probability 1/16, so the probability to get exactly one head in 4 flips is 1/16 + 1/16 + 1/16 + 1/16 = 4/16 = 1/4.

erica would now have 20 bottles of water because 26-6=20.

i hope this : )