Question $2$

TABLE $3$:$1\mathrm{.}2$

CONCRETE PROPERTIES AT $28$ DAYS

$\backslash$table$[[f_c^{\text{'}}(MPa),20,25,32,40,50,65,80,100],[f_{cm}(MPa),22,28,35,43,53,68,82,99],[E_c(MPa),24000,26700,30100,32800,34800,37400,39600,42200]]$

Table $3\mathrm{.}1\mathrm{.}2$ appears in AS$3600$ as shown above. The mean compressive strength for concrete with a characteristic compressive strength of $100$MPa is:

$($a$)$ incorrect because the mean compressive strength value is the characteristic compressive strength $+1\mathrm{.}64$ x standard deviation

$($b$)$ incorrect because the mean compressive strength value is the characteristic compressive strength $-1\mathrm{.}64$ standard deviation

$($c$)$ correct because the mean compressive strength value is the characteristic compressive strength $-1\mathrm{.}64$ standard deviation

$($d$)$ correct because it's in the Concrete Structures Code

$($e$)$ None of the other answers is correct