Cyclopropane and oxygen at partial pressures 170 torr and 570 torr respectively are mixed in a gas cylinder. What is the ratio of the number of moles of cyclopropane to the number of moles of oxygen \[(n{{C}_{3}}{{H}_{6}}/n{{O}_{2}})\]

• A. \[\frac{170\times 42}{570\times 32}=0.39\]
• B. \[\frac{170}{42}/\left( \frac{170}{42}+\frac{570}{32} \right)\approx 0.19\]
• C. \[\frac{170}{740}=0.23\]
• D. \[\frac{170}{570}=0.30\]