There are two events described in this exercise.

Jeremy scores $1350$ on the SAT.
Jeremy scores $23$ on the ACT.

Let's recall what it means for two events to be independent.

Independent Events
Two events are independent if neither one affects the probability of the other.

In the given case, Jeremy scoring a particular result on the SAT does not affect the probability of him getting a particular score on the ACT. Likewise, Jeremy scoring a particular result on the ACT does not affect the probability of him getting a particular score on the SAT. Neither of these events affects the probability of the other, so these are independent events.

Extra

Another Example of Independent Events at Music Store

Let's consider two events that occured for Jeremy while visiting a music store after finishing his SAT and ACT tests.

Event A is that Jeremy has decided to buy a vinyl record of his favorite band Bay Lights.

Event B is that Jeremy received a text message from a friend about a bicycle ride later that day.

In this scenario, Jeremy deciding to buy a vinyl record of his favorite band does not affect the probability of receiving a text message about a bicycle ride. Also, receiving a text message about a bicycle ride does not affect the probability of Jeremy deciding to buy a vinyl record. The two events do not affect the probability of the other, so they are considered independent events.

Exercise