Asurvey asked a group of students to choose their favorite type of music from the choices of rock, hip-hop, and country. the results of the survey are shown in the graph.

based on the graph, how many more students in a class of 270 students would be expected to choose country than rock?
a) 10
b) 20
c) 30
d) 60

"how many more students in a class of 270 students would be expected to choose country than rock?"

In order to answer this question, we need to know how many students choose country, and how many students choose rock

From the graph, we could read that 30 students choose country, and 20 students choose rock.

So that, the difference between these two number is 30-20= 10 more students choose country than rock

But the students' number is 270, not 90 as is in the graph

so we would multiply our result by 3 to get the right number of students

10*3=30 students

I hope that helps!