A gas can be taken from A to B via two different processes ACB and ADB.

When path ACB is used 60 J of heat flows into the system and 30 J of work is done by the system. If path ADB is used work done by the system is 10 J, the heat flow into the system in path ADB is

For the ABC as shown in the figure below.

According to the first law of thermodynamics, heat supplied, $\mathrm{\Delta Q}=$work done $\left(\mathrm{\Delta W}\right)$ + internal energy  $\left(\mathrm{\Delta U}\right)$

$\Rightarrow {\mathrm{\Delta Q}}_{\mathrm{CB}}={\mathrm{\Delta W}}_{\mathrm{ACB}}+\left({\mathrm{U}}_{\mathrm{B}}-{\mathrm{U}}_{\mathrm{A}}\right)$ Substituting the given values, [where $\mathrm{\Delta U}={\mathrm{U}}_{\mathrm{B}}-{\mathrm{U}}_{\mathrm{A}}$)

${\mathrm{U}}_{\mathrm{B}}-{\mathrm{U}}_{\mathrm{A}}=60-30=30\mathrm{J}$ Similarly for the ADB as shown in the figure below,

$\begin{array}{l}\Rightarrow {\mathrm{\Delta Q}}_{\mathrm{ADB}}={\mathrm{\Delta W}}_{\mathrm{ADB}}+\left({\mathrm{U}}_{\mathrm{B}}-{\mathrm{U}}_{\mathrm{A}}\right)\\ \Rightarrow {\mathrm{\Delta Q}}_{\mathrm{ADB}}=10+30\\ =40\mathrm{J}\end{array}$