In attrition test used to find the rate of wear of stones, wear should be equal to or less than ___________ for good building stone.

In attrition test used to find the rate of wear of stones, wear should

1.	In attrition test used to find the rate of wear of stones, wear should be equal to or less than ___________ for good building stone.
A.	2%
B.	3%
C.	5%
D.	6%
Answer» B. 3%