Answer:
the neighbor has in total 24 chickens.
Step-by-step explanation:
Total number of animals  =  31
Let the number of roosters  = k
Then , the number of chickens he has  = 2 k + 10
Now, according to the question:
(k) Â + ( 2k + 10) Â = 31
or, 3k = 31 -10 Â
⇒ 3k = 21, or  k = 21/3
⇒ k = 7
Hence, the number of roosters he has = k = 7
And the number of chicken he has  2k +  10.
= (2 x 7) Â + Â 10
= 24
Hence, the neighbor has total 24 chickens.