Q. A mixture of 10% C6H6 vapour in air at 25°C and 750 mm Hg has a dew point of 20°C. Its dew point at 30°C and 700 mm Hg will be around __________ °C.

• (A) 21.7
• (B) 20
• (C) 27.3
• (D) 18.7