a dragon lived in a cave
the dragon doubled in size every day after 20 days the dragon filled the cave
after how many days did the dragon half fill the cave
+37097 If the dragon DOUBLES in size each day.....the day prior it is 1/2 size
full cave = 20 days previous day it was 1/2 size of the cave so answer is 19 days to fill 1/2 cave
