$V=5 \ell$

$v_{\operatorname{rms}}=\sqrt{\frac{3 R T}{M_{m}}}$

$\Rightarrow \frac{1}{2}\left(n M_{m}\right) v_{r m s}^{2}=\frac{3}{2} n R T=\frac{3}{2} p v$

Translational $K.E.$ of all molecules

$=\frac{3}{2} P V$

$\therefore \frac{3}{2} P \times 5 \ell=3000 \mathrm{J}$

$\mathrm{P}=400 \mathrm{J} / \mathrm{l}$

Total $K.E.$ of $10 l$ of gas at Pressure $2 \mathrm{P}$ for a monoatomic

gas $=\frac{3}{2} \times 800 \times 10=12000 \mathrm{J}$

Total $K.E.$ of $101,2 \mathrm{P}$ pressure for a diatomic gas $=5 / 2 \mathrm{PV}$

$=\frac{5}{2} \times 800 \times 10=2000$ Joules

$Note:$ In options its asked total $K.E.$ not translational $K.E$