Final answer:
Brad practiced violin for 20 minutes yesterday, and he plans to practice longer today. The inequality representing this is t > 20, where t represents today's practice time in minutes.
Step-by-step explanation:
The student is asking for an inequality that models the scenario of Brad practicing the violin for a longer time than he did yesterday.
Since Brad practiced for 20 minutes yesterday, the inequality to represent the time t that Brad will practice today is t > 20.
This inequality states that the time Brad will practice today is greater than 20 minutes.
The use of the 'greater than' symbol (>) is appropriate because Brad plans to practice for a longer duration than he did the previous day.