Answer
more than 200 text messages
Work Step by Step
Step 1. Assume the number of text messages is $x$; then Plan B will have a cost of $13+0.06x$.
Step 2. For plan A to be better, the cost of plan B needs to be higher than that of plan A. We have $13+0.06x\gt 25$
Step 3. Solving the above inequality, we have $0.06x\gt12$ and $x\gt200$. Thus, for more than 200 text messages, plan A would be better.