On a cold night in antarctica. the temperature dropped 0`c to -21c in 6 hours. what is the average temperature change per hour( give me the answer)

Answer question above and explain each step : )

Iwill give brainliest only if your correct the words subsequent and submerge both contain the prefix sub. based on this information, what does the prefix sub most likely mean? a) under or secondary b) true or verifiable c) tricky or difficult d) around or centered on

If 20% of a number is 35, what is 50% of that number?