Aiden 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 students in a class of 360 students would be expected to choose hip-hop or rock as their favorite type of music?
Hiphop has 40
Rock has 20

240

Step-by-step explanation:

20% of the students like rock and 40% like hip-hop. That means that 60% of the 360 students would be expected to choose one of the two. Because you don't know the other 10%, you would assume that they would have the same ratio of students who like the country to those who like rock and hip-hop. 60 is 2/3 of 90, so you would expect 2/3 of the students to like hip-hop or rock. 2/3 of 360 is 240.

(this is not my handlely work; I not very good at explaining)