(b) 12
Let the number of buffaloes be b and
the number of ducks be d. Then,
Number of legs of buffaloes = 4 × b = 4b
Number of legs of ducks = 2 × d = 2d
Total number of heads = 2 (b + d)
According to the question,
4b + 2d = 2(b + d) + 24
\(\Rightarrow\) 4b + 2d = 2b + 2d + 24
\(\Rightarrow\) 2b = 24
\(\Rightarrow\) b = 12.