Array constraint. Each row total should be 100, with each element less than 80. I want to understand how to do this using only sum method of array

In reply to dave_59:

Hi Dave, Could you please help me understand why the third operand should be 101. Why cant it be 0
“That third operand needs to be a value greater than 100 so that item < 80 must always be true.” How will that work?