Question

Why do fish and frog lay egg in hundreds whereas a hen lays only one egg at one time

Answer 1

it depends upon size

frog and fish eggs are very much small

whereas hens egg is big as compare to fish and frog

Answer 2

Bhai bhele wo 100 eggs dete hai per Kuch hi zinda rehete hai

and

the no.of ovum is released more in fish and frog while copulation but in hen

only one ovum is released so

this is your answer