ms. gomez's class counted by 20s. Each person said a number. How many people counted to get to 300? How many counted to get to 600? How do you know? ​

Unclearly worded problem.   What nember did thet start with?   I can start at 65 and count by 20's  65 85 105 etc

If they started at ZERO and the first person said '20' and the second said '40' etc ....then if they counted to 300:

300/20 = 15    600/20 = 30

Well you can divide by 20 so to get to 300 15 people counted because 300/20=15 and to get to 600 30 people counted because 600/20=30