Sheldon only drinks hot chocolate in months with an "r" in them. Thus, his quirk doesn't allow him to drink hot chocolate in the consecutive months of May, June, July, and August, which spans the summer season in the Northern Hemisphere.
Leonard estimates the height of the lift shaft by timing how long it takes until he hears breaking glass. This is done by multiplying the number of seconds by itself and then multiplying by 16 (to get the height in feet) or 5 (to get it in meters). Given that the time is about a second and half, Leonard's estimate of 30 feet is a reasonable one, which isn't bad, given that he is drunk at the time.
The gang uses the returning laser to determine the distance to the moon. Leonard reports that the laser echo took two and a half seconds. Given that the speed of light is 300 000 kilometers per second, the total distance to the moon and back must be 750 000 kilometers, which means that the reflector on the moon's surface must be 375 000 kilometers from the Earth.