The notation p -> q refers to a conditional statement.
Conditionals are only false when the first part (p) is true while the second part (q) is false. In other words, the template true --> false ultimately leads to a false statement. Otherwise, the entire thing is true.
In our case, we have something that fits the "true -> false" template, so that's why p -> q is never true when p = true and q = false.
So x=earned x>200 they paid their parrents 28 for supplies (this assumes that they paied 28 altogether and not 28 each) so subtract 28 from pay new pay=y y>200-28 y>172 divided it among themselves (3) 172/3=57 and 1/3=57.33 they each earned more that $57.33