Heat And Thermodynamics

The ratio of the specific heat capacities of a gas is 1.5 . When the gas undergoes adiabatic process, its volume is doubled and pressure becomes $p_1$. When the gas undergoes isothermal process, its volume is doubled and pressure becomes $p_2$. If $p_1=p_2$, the ratio of the initial pressures of the gas when it undergoes adiabatic and isothermal processes is