$T_{50} $ of first order reaction is 10 min storing with $10\; mol^{-1}$ rate after 20 min is

Question

$\begin{array}{1 1} 0.0693 \;mol\; l^{-1} \; min^{-1} \\ 0.0693 \times 2.5 \;mol\;l^{-1}\;min^{-1} \\ 0.0693 \times 5 \;mol\;l^{-1}\;min^{-1} \\0.0693 \times 10 \;mol\;l^{-1}\;min^{-1}\end{array} $