A U-tube manometer contains two manometric fluids of densities 1000 kg m^-3 and 600 kg m^-3. When both the limbs are open to atmosphere, the difference between the two levels is 10 cm at equilibrium, as shown in the figure. The rest of the manometer is filled with air of negligible density. The acceleration due to gravity is 9.81 m s^-2 and the atmospheric pressure is 100 kPa. How much absolute pressure (in kPa) has to be applied on the limb 'P' to raise the fluid in the limb 'Q' by another 20 cm?