Two different metal bodies A and B of equal mass are heated at a uniform rate under similar conditions. The variation of temperature of the bodies is graphically represented as shown in figure. The ratio of specific heat capacities is 

Let masses of two bodies A and B be $m_A$ and $m_B$ and $m_A=m_B=m$  
As we know that $\Delta Q/\Delta t=ms\Delta T/\Delta t$   , Where,$\Delta Q/\Delta t=$  rate of heat of change
 $m=$mass, $s=$ specific heat and  $\Delta T=$ change in temperature.
Since, ${\left(\frac{\mathrm{\Delta Q}}{\mathrm{\Delta t}}\right)}_{\mathrm{A}}={\left(\frac{\mathrm{\Delta Q}}{\mathrm{\Delta t}}\right)}_{\mathrm{B}}$         $\Rightarrow m{S}_A{\left(\frac{\Delta T}{t}\right)}_A=m{S}_B{\left(\frac{\Delta T}{t}\right)}_B$

$\Rightarrow \frac{{\mathrm{S}}_{\mathrm{A}}}{{\mathrm{S}}_{\mathrm{B}}}=\frac{{\left(\frac{\mathrm{\Delta T}}{\mathrm{t}}\right)}_{\mathrm{B}}}{{\left(\frac{\mathrm{\Delta T}}{\mathrm{t}}\right)}_{\mathrm{A}}}=\frac{\frac{90}{6}}{\frac{120}{3}}=\frac{3}{2\times 4}=\frac{3}{8}$