A piston performs work of 210. L atm on the surroundings, while the cylinder in which it is placed expands from 10. L to 25 L.

A piston performs work of 210. L atm on the surroundings, while the cylinder in which it is placed expands from 10. L to 25 L. At the same time, 45 J of heat is transferred from the surroundings to the system. Against what pressure was the piston working?