<human>:  Miss Molly surveyed her class of 30 students about their favorite color. Half of the class answered green, one-third of the girls answered pink, and the rest of the class answered yellow. If there are 18 girls in the class, how many students like yellow best?
<bot>: How many students answered green? ** 30/2 = <<30/2=15>>15 students answered green.
How many girls answered pink? ** 18/3 = <<18/3=6>>6 girls answered pink.
How many students answered either green or pink? ** So, 15 + 6 = <<15+6=21>>21 students answered either green or pink.
How many students answered yellow? ** Therefore, 30 - 21 = <<30-21=9>>9 answered yellow.
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