Of $$60$$ flamingos, $$40$$ stood on $$2$$ legs and $$20$$ stood on $$1$$. All together, these flamingos stood on $$[(40\times2)+20]$$ legs $$=100$$ legs. 
Of $$60$$ flamingos, twice as many stood on $$2$$ legs as stood on $$1$$. All together, on how many legs did all of these flamingos stand? 

a) $$80$$ 
b) $$90$$ 
c) $$100$$ 
d) $$110$$ 
e) $$120$$ 