a set s of characters is defined recursively by
1. a and b belong to s.
2. if x belongs to s, so does xb.
which of the following string belong to s?
a. a
b. ab
c. aba
d. aaab
e.

Which of the following three dimensional figures has a circle as it’s base

East black horse $0.25 total budget is $555 it'll cost $115 for other supplies about how many flyers do you think we can buy

According to the 2008 u. s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.