The pebbles rolled into the open Areas between the golf balls.
He then asked the students again if the jar was full. They agreed it was.
The professor next picked up a box of sand and poured it into the jar.
Of course, the sand filled up everything else..
He asked once more if the jar was full. The students responded with a unanimous 'yes.'
The professor then produced two cups of coffee from under the table and poured the entire contents into the jar, effectively filling the empty space between the sand. The students laughed.
'Now,' said the professor, as the laughter subsided,