The answer would be 21/50. If you have numbers with a few zeros you can cross one of the top amd bottom until you reach the other numbers, if that makes sense. You can changd 420/1000 to 42/100. Then just keep dividing it by a numner that goes evenly into both the numerator and denominator.
Answer:

Step-by-step explanation:
4 times 4 is 16 so while both are in power so we can do this like that
Answer:
around 30
Step-by-step explanation: dont quote me though