In a poll, students were asked to choose which of six colors was the favorite. The circle graph shows how the students answered. If 3000 students participated in the pool, how many chose orange, red, or blue?

Okay, here we have this:
Considering the provided information, we are going to calculate the requested amount of students, so we obtain the following:
To do this, what we will do is add the percentages of the requested colors and multiply it by the total number of students, then we have:
Students who chose orange, red, or blue=(9%+16%+35%)*3000
Students who chose orange, red, or blue=(60%)*3000
Students who chose orange, red, or blue=0.6*3000
Students who chose orange, red, or blue=1800
Finally we obtain that 1800 students chose orange, red, or blue.