Carbon is burned with dry air. The volumetric analysis of the products produces 10.06 percent CO2, 0.42

Question:

Carbon is burned with dry air. The volumetric analysis of the products produces 10.06 percent CO2, 0.42 percent CO, and 10.69 percent O2 (and the rest N2). Determine.
(a) The air-fuel ratio on a mass basis.
(b) The percentage of theoretical air (λ) used in the reaction, and (b) the equivalent ratio (φ).