Work done on heating one mole of monoatomic gas adiabatically through ${20}^{0}C$  is W. Then the work done on heating 6 moles of rigid diatomic gas through the same change in temperature 

For adiabatic process,  I law of thermodynamics is  $W=\Delta U$
For 1 mole of monoatomic gas,  $U=\frac{3}{2}KT$
For 1 mole of diatomic gas,  $U=\frac{5}{2}KT$
$\therefore W_1$  for one mole of monoatomic gas, 

$W_1=\frac{3}{2}K\Delta T=15K\Delta T=W_1$
 
For 6 moles of diatomic. 
 $W_2=\frac{6.5}{2}K\Delta T=15K\Delta T$

$\therefore W_2=15K\Delta T=10$

$1.5K\Delta {\rm T}=10W$