What are the answers to these 3 problems?

Tod does not have any cookies. david gives jeff 8 cookies. then he splits half of the cookies he has left with tod. david let’s c represent the number of cookies that he starts with. he finds the number of cookies that tod has is 1/2 the difference of c and 8. write an expression to represent the number of cookies that tod has.

Azul has 4 green picks and no orange picks.you add orange picks so that there are 2 orange picks for every 1 green pick.how many picks are there now.

If there are 825 students at cherry hill high school and 4 out of every 5 students voted in the student council election, how many students voted?