In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half of the lake?

Question

studio-games · Answer

Ok lemme see.

anonymous · Answer

Simple solution.... If every day the size of the patch doubles and it takes 48 days to completely fill the lake; then on the 47th day the lake would be half covered.  Why?  

If the size of the patch is half the size of the lake, then one day later the patch has doubled.

studio-games · Answer

it is half full on day 47
every day it doubles 
so on day 48 it is full

anonymous · Answer

And double of 1/2 is 2*(1/2)=1... i.e. the size of the whole lake

anonymous · Answer

So as studio also pointed out, it takes 47 days for the patch to reach the half-way point, and the last day it fully covers the lake.