Thermodynamics: JEE Main 2025 Physics question

A Carnot engine (E) is working between two temperatures 473K and 273K. In a new system two engines - engine $E_1$ works between 473K to 373K and engine $E_2$ works between 373K to 273K. If $\eta_{12}$, $\eta_1$ and $\eta_2$ are the efficiencies of the engines E, $E_1$ and $E_2$, respectively, then