Use R=8.3 J/mol-K wherever required. The weather report reads,

Use $\mathrm{R}=8.3 \mathrm{~J} / \mathrm{mol}-\mathrm{K}$ wherever required.

The weather report reads, "Temperature $20{ }^{\circ} \mathrm{C}$ : Relative humidity $100 \% "$. What is the dew point?