A tube manometer contains two manometric fluids on densities 1000 kg/m³ and 600 kg/m³. When both limbs (P and Q) are open to the atmosphere, the difference between the two levels is 10 cm at equilibrium. The rest of the manometer is filled with air of negligible density. The acceleration due to gravity is 9.81 m/s² 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?