text: estimate the temerature at altitudes of 10,000, 15,000, 24,000 and 30,000 feet?   this is not a mathematics question .. as there is no condition given .. however, i estimate it based on the following assumptions:  1. more you go up, temp will fall. 2. while travelling by air, (at 35,000 feet) outside temperature is around - 15 degree celcious. (this might vary from place to place and season to season though) 3. assume the temperature at ground level (altitude = 0) 30 degree celcious (this will vary from place to place though)  now we have two points  altitude = 0, temp = 30 degree celcious altitude = 35,000 feet, temp = - 15 degree celcious  so for an altitude difference of 35,000 feet temp drops by 45 degree celcious  the rough estimate could be done like this:  for 10,000 feet altitude difference, temp will fall by (45/35000)*10000 or 12.85 degree. so temp at 10,000 feet altitude will be 17.15 degree celcious  for 15,000 feet altitude difference, temp will fall by (45/35000)*15000 or 19.28 degree. so temp at 15,000 feet altitude will be 10.72 degree celcious  for 24,000 feet altitude difference, temp will fall by (45/35000)*24000 or 30.86 degree. so temp at 24,000 feet altitude will be -0.86 degree celcious  for 30,000 feet altitude difference, temp will fall by (45/35000)*30000 or 38.57 degree. so temp at 30,000 feet altitude will be -8.57 degree.