
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A school has a student population of 150 in grade 10, 180 in grade 11, and 210 in grade 12. To investigate the visual acuity of the students, a sample of 72 students needs to be selected. If stratified sampling is used, the number of students to be sampled from grade 10 and grade 11 combined is ____.

Present the answer in LaTex format: \boxed{Your answer}
user