GATE Civil Engineering (CE) 2023 Shift 2 Solved Paper

A system of seven river segments is shown in the schematic diagram. The R_i’s, Q_i’s, and C_i’s (i = 1 to 7) are the river segments, their corresponding flow rates, and concentrations of a conservative pollutant, respectively. Assume complete mixing at the intersections, no additional water loss or gain in the system, and steady state condition. Given: Q₁ = 5 m³/s ; Q₂ = 15 m³/s ; Q₄ = 3 m³/s ; Q₆ = 8 m³/s ; C₁ = 8 kg/m³; C₂ = 12 kg/m³; C₆ = 10 kg/m³. What is the steady state concentration (in kg/m³, rounded off to two decimal place) of the pollutant in the river segment 7 ? ______