Help with linux commands
 

how do I use the command grep, to express the same thing as wc -l?

and how would I write a command(using regular expressions) to find the tree of directories with the files that have a digit and the letter e.

last question how would i finds if the days that were left in the year the year is a mutiple of five i have
$(( (365- $(date +%j)) )) but it wont tell me if its a mutiple of five.

This reads an awful lot like homework. Why would you want to know how to use grep in a certain way if you can just use wc... unless it's a specific homework question? Assuming that this is homework, please respect the rules you have agreed to and not expect help with queries such as these.

Even if it is homework ... at least be decent enough to give it a go first before you blatantly try to have someone else do it for you.