Whats the answer to this question?

Asap 25 pts brainliest to right best/answer

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?