IIT JAM 2026 Question 56: Monopolistic competition and oligopoly

A duopoly market has demand $P=120-0.6Q$ with $Q=Q_1+Q_2$, and cost functions $C_1=6Q_1$ and $C_2=0.5Q_2^2$, where $P$ is unit price, $C_i$ is the cost function and $Q_i$ is the output of firm $i$. The total output $(Q)$ produced by the duopolists ignoring their interdependence is ________ (rounded off to two decimal places).