So we know that cows have 4 legs and chickens have 2 so since there are 10 cows and 16 chickens you can multiply 4 times 10 and that gives you 40 then multiply 16 times 2 and that gives you 32. Then you add the 40 and 32 and that gives you 72 so you are missing 2 legs which means that it is 10 cows and 17 chickens which gives you 74 legs but only 27 animals so i have no clue how many there is of each :);)