Solution:
Given diameter of the hole, d = 30 cm
radius of the hole, r = d/2 = 30/2 = 15 cm
Height of the cylindrical hole, h = 70 cm
Volume of the cuboidal block = lbh
= 70×30×30
= 63000 cm3
Volume of cylindrical hole = r2h
= (22/7)×152×70
= 22×225×10
= 49500 cm3
Volume of the wood left in the block = 63000-49500 = 13500 cm3
Hence the volume of the wood left in the block is 13500 cm3.