Q.Calculate the output voltage.

Multiply the stage gains: non-inverting $\left(1+\tfrac{560}{4.3}\right)\approx131.2$, and two inverting stages each $-\tfrac{560}{33}\approx-16.97$, giving an overall gain of about $+37{,}790$ applied to $80\ …

[!TLDR]

The three stages give an overall gain of about $+37{,}790$, so the $80\,\mu\text{V}$ input produces $V_O\approx3.0233\text{ V}$.

The overall gain is the product of the three stage gains.

Stage 1 (non-inverting, source at $+$):

Stage 2 (inverting):

Stage 3 (inverting):

Overall gain:

Hence

$V_O=A\times80\,\mu\text{V}\approx37{,}790\times80\times10^{-6}\approx3.0233\text{ V}$ …