Answer: 6 animals should go in each pen.
Step-by-step explanation:
Total sheep = 54
Total cows = 24
Total pigs = 30
Highest number of animals are possible in each pen such that animals are distributed in pens with the same number = Greatest common divisior (54,24, 30)
54= 6 x 9
24= 6 x 4
30 = 6 x 5
So, Greatest common divisior (54,24, 30) = 6
Hence, 6 animals should go in each pen.