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
Answer:
5
Step-by-step explanation:
Supplementary means they add up to 180
X + 54 = 180
180-54= x
X = 126
126+54=180?
Yep
So your answer is
126
Answer:
3 cans
Step-by-step explanation:
A = lw
a = 20 x 8 = 160
a = 40 x 8 = 320 
Together this is 480 
I would need 3 cans.