The maximum compressive strength on 15 cm cubes of M 20 grade concrete at 7 days, should be a minimum of
A.	7 N/mm2
B.	10 N/mm2
C.	15 N/mm2
D.	20 N/mm2
Answer:B
The maximum compressive strength on 15 cm cubes of M 20 grade concrete at 7 days, should be a minimum of
A.	7 N/mm2 B.	10 N/mm2 C.	15 N/mm2 D.	20 N/mm2