10 x 4 + 20 x 2 + 2 + 2 + 4 = 88. 
SASMO 2016 P2 Q6  Uncle John has a farm. His wife and his two sons are staying with him in the farm. They raise 10 cows and 20 chickens. How many total legs are there in the farm? 
1. $$60$$ 
2. $$80$$ 
3. $$86$$ 
4. $$88$$ 
5. $$120$$ 