A class A pan was set up adjacent to a lake. The depth of water in the pan at the beginning of a certain week was $390$ mm$.$ In that week there was a rainfall of $90$ mm and $30$mm of water was removed from the pan to keep the water level within the specified depth range. If the depth of the water in the pan at the end of the week was $380$ mm$,$ calculate the pan evaporation.

Using a suitable

pan coefficient estimate the lake

evaporation in that week.