Step 1
Given;

Required; Find how many signatures each will have if the trend continues and they have a tie.
Step 2
Find the system of equations where x represents the number of minutes

Step 3
For there to be a tie, we will equate the number of signatures of Gavi To that of Isabelle

Step 4
Find how many signatures each of them will have

Therefore, Gavin will have the number of signatures below;

Therefore, Isabelle will have the number of signatures below;

Hence, both Gavin and Isabelle will have 239 signatures each after 42 minutes