At the surface of the Earth, atmospheric pressure is 760 mm Hg. What atmospheric pressure will be at an altitude of 1440 m?

With small rises, on average, for every 12 m, the pressure increases by 1 mm Hg.
Atmospheric pressure equal to the pressure of a column of mercury 760 mm is considered normal and equal to 101300 Pa.
Let’s make the proportion:
760 mm Hg = 101300 Pa
1 mm Hg = x Pa
Hence, x = 101300 * 1/760 = 133 Pa.
As you rise, the pressure decreases.
We divide the height by 12, find how much the pressure of the mercury column has decreased at this height:
1440/12 = 120 mm Hg
Mine pressure:
760-120 = 640 mm Hg
Let’s translate into the SI system:
640 * 133 = 85120 Pa.
Answer: the pressure in the mine is 640 mm Hg. or 85120 Pa.