The number of molecules present in  $1.12\times {10}^{-5}cc$ of a gas at STP

1 mole gas = $6.02\times {10}^{23}$ molecules $=22400cc$

$x=1.12\times {10}^{-5}cc$

$\Rightarrow x\times 22400cc=1.12\times {10}^{-5}\times 6.02\times {10}^{23} molecules$