Very good kata for practice !!! ;)

Same for me !!! Not good at all !!!

Can you guys help me , why doesn't my average function works :
class Array
def square
# create your square method here
self.map {|n| n ** 2}
end

def cube()
self.map {|n| n**3}

end

def average()

self.map ((sum.inject(0) { |z,x| sum + x }) / self.length)

end

def sum(x)

sum.inject(0){|sum,x| sum + x }
end
def even()

even.values_at(* even.each_index.select {|i| i.even?})

end
def odd()
odd() { return this.filter(odd(x) { return 0 == x % 2; }); }
end

now fill in the rest

end

when I tested it's giving "wrong number of agruments."