Answer:
12
Explanation:
Binomial expression:

Where n = No. of trials i.e. no. of times experiment occur
p= Probability of success
q= Probability of Failure
r= No. of success.
We are given that Sonia rolls a six sided number cube 12 times and records of she rolls a 2.
Since here the cube was rolled 12 times.
Thus n =12
So, No. of trials =12
Hence the number of trials for this binomial experiment is 12.