text: This is not a mathematics question .. as there is no condition given .. however, I estimate it based on the following assumptions:\n\n1. More you go up, temp will fall.\n2. 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)\n3. Assume the temperature at ground level (altitude = 0) 30 degree celcious (this will vary from place to place though)\n\nnow we have two points\n\naltitude = 0, temp = 30 degree celcious\naltitude = 35,000 feet, temp = - 15 degree celcious\n\nso for an altitude difference of 35,000 feet temp drops by 45 degree celcious\n\nThe rough estimate could be done like this:\n\nfor 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\n\nfor 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\n\nfor 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\n\nfor 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.