Table:
text: Air quality index
United States
United States
C_low_ C_high_ I_low_ I_high_ Category
0 12.0 0 50 Good
12.1 35.4 51 100 Moderate
35.5 55.4 101 150 Unhealthy for Sensitive Groups
55.5 150.4 151 200 Unhealthy
150.5 250.4 201 300 Very Unhealthy
250.5 350.4 301 400 Hazardous

Question: How many different C_{high} values are there for the good category in the United States Air Quality Index?

Question: What is the C_{high} of the United States if the C_{low} is 250.5 on the Air Quality Index?

Question: What is the i_{high} value when C_{low} is 250.5 in the United States Air Quality Index?

Question: What is the C_{low} value when C_{high} is 12.0 on the US Air Quality Index?

Question: In how many different categories does C_{low} 35.5 fall in the US Air Quality Index?