Answer:
x + y + z = 272 - - - - - - (1)
x = 3y - - - - - - - - - - - - - (2)
z = 32 + y - - - - - - - - - - (3)
Explanation:
Let :
Number of pop songs = x
Number of rock songs = y
Number of hophops = z
Sum of the three types of songs = 272
x + y + z = 272 - - - - - - (1)
Pop is 3 times Rock :
x = 3y - - - - - - - - - - - - - (2)
Hiphop is 31 more than rock
z = 32 + y - - - - - - - - - - (3)