Ronald McDonald, a farmer, has chickens, goats and cows in his farm. He has $$40$$ chickens and goats combined. He notices that $$3$$ times the number of his chickens is $$5$$ times the number of his cows. On the other hand, $$2$$ times the number of goats is $$10$$ times the number of his cows. Help Ronald McDonald determine the total number of animal feet in his farm. 
Overseas Competition->Knowledge Point->Word Problem Modules->Chicken-Rabbit Problems