The first thing we must do for this case is find the number of total guitarists.
We have then:
We now look for the relationship between the number of guitarists playing jazz alone to the total number of guitarists.
We have then:
Where,
x: number of guitarists playing jazz alone
From here, we clear the value of x.
Then, the number of guitarists who play classical solo is:
Answer:
30 guitarists play classical solos in the contest