Answer:
[tex]Red = 29[/tex]
Step-by-step explanation:
Given
[tex]Total = 60[/tex]
[tex]Purple = 11[/tex]
[tex]Green = 20[/tex]
Required
Number of red marbles, without counting
To do this, we simply subtract the sum of the purple and red marbled from the total marbles.
So, we have:
[tex]Red = Total - (Purple + Green)[/tex]
[tex]Red = 60 - (11 + 20)[/tex]
[tex]Red = 60 - 31[/tex]
[tex]Red = 29[/tex]