Answer:
Option B.
Explanation:
It is given that all of the students of Music High School are in the band, the orchestra, or both.
Students only one group = 80%
Students in both groups = 100%-80% = 20%
Students in band only = 50%
Students in band = Students in band only + Students in both groups
= 50% + 20% = 70%
Students in orchestra only = 100% - 70% = 30%
There are 119 students in the band.
Let total number of student be x.




Total number of students is 170.
We know that 30% of all students are in orchestra only.

Therefore, the correct option is B.