When the bulb of a constant-volume gas thermometer is placed in a beaker of boiling water at 100°C?

When the bulb of a constant-volume gas thermometer is placed in a beaker of boiling water at 100°C, the pressure of the gas is 223 mmHg. When the bulb is moved to an ice-salt mixture the pressure of the gas drops to 159 mmHg. Assuming ideal behavior, as in the figure below, what is the [...]