To find the number of seniors who did not vote for the Copacabana, we need to first determine the total number of seniors in the class.
Let's represent the total number of seniors in the class as 'x'.
According to the given information, 42 seniors voted for the Copacabana, which is equivalent to 2/9 of the senior class.
So, we can set up the following equation to solve for 'x':
2/9 * x = 42
To solve for 'x', we can multiply both sides of the equation by 9/2:
(2/9 * x) * (9/2) = 42 * (9/2)
Simplifying the equation gives us:
x = 42 * (9/2) * (9/2)
Now we can calculate 'x':
x = 189
Therefore, the total number of seniors in the class is 189.
To find the number of seniors who did not vote for the Copacabana, we subtract the number of seniors who did vote for it from the total number of seniors:
Number of seniors who did not vote for the Copacabana = Total number of seniors - Number of seniors who voted for the Copacabana
Number of seniors who did not vote for the Copacabana = 189 - 42
Number of seniors who did not vote for the Copacabana = 147
Therefore, 147 seniors did not vote for the Copacabana.