-Before the experiment there was 530.2g of salt in the beaker.
-During the experiment each student removed 47.36g of salt from the beaker:
47.36g x 3 students= 142.08g of salt
Now you have to find how much grams of salt was left in the beaker at the end of the beaker:
Total amount-Amount removed by students: 530.2g-142.08g=388.12g of salt at the end of the experiment.