Question 1006500
Hi there,
Formula for the volume of
a sphere = 4/3 Pi r^3
The volume of a sphere with
a radius of 1 cm
= 4/3 pi 1^3
= 4/3 pi.
If a hole is drilled removing half
the volume of the said sphere, the 
volume of the hole equals =
1/2 x 4/3pi
= 2/3pi
or 2.09 cm^3 (2 decimal places)
Hope this helps :-)