Answer:

20

Let’s simplify the language.  If 1.5H can lay 1.5E in 1.5D then 3H can lay 3E in 1.5D.  This means that 3H can lay 6E in 3D.  3H can lay 12E in 6D.

In order to get 5H we multiply the hens by (5/3).  We also need to multiply the eggs they lay by (5/3) and this gives us 20.