Question 38645
There are 18 animals in the barnyard. Some are chickens and some are cows. I counted 50 legs in all. How many of the animals are chickens and how many are cows?
Define variables:
c=number of chickens
o=number of cows
Define equations:
c+o=18
2c+4o=50
Combine:
-2c-2o=-36
+
2c+4o=50
=
2o=14
o=7
Substitute:
c+o=18
c+7-18
c=11
Eleven chickens and seven cows are in barnyard!