Answer:
91.7°C
Step-by-step explanation:
We suppose you have a formula to work from. However, that is not supplied with this problem statement, so we looked one up.
The formula in the attachment is supposed to have good accuracy in the temperature range of interest. It gives vapor pressure of water in kPa, not mmHg, so we needed the conversion for that, too.
560 mmHg corresponds to about 74.66 kPa. The attached "Buck equation" formula is used to find the corresponding temperature. The exponential equation could be solved algebraically using logarithms and the quadratic formula, but we choose to find the solution graphically.
Water boils at about 91.7 °C on Mt. Whitney.