<PRE><B>Question 1098602</B>
Volume of pyramid = 1/3 *s^2*h 
V= 1/3 *30^2*8= 2400 cm^3

Volume of cylindrical portion l*b*h 
V= 30*30*150= 135000 cm^3 

TOTAL volume =137400 cm^3

Surface area of the pyramid section of the post=4 pi r l 
4*area of one triangle
4*1/2 *30*17=1020 cm^2

The base is reduced by 1/2 - prism
 If the edges are halved they will become 15 cm each. Volume now will be (15*15*150
 =33750 cm^3

pyramid volume 
1/3*15*15*8=600 cm^3

prism volume = 15*15*150=34350 cm^3

Number of posts =137400/34350 =4 posts from the same volume of concrete




</PRE>