Question

_+_+_+_+80+90+=100 what we will add in the blank the answer will come 100

Answer 1

It is not a riddle instead of a riddle it is a joke.
It is like that Akad Bakkad Bambe Bo, Assi nabbe pure Sau
So answer will be Akkad + bakkad + bambe + bo + 80 + 90 = 100.

Answer 2

Akkad + bakkad + bambe + bo + 80 + 90 = 100.