Heat and Thermodynamics

A spherical soap bubble inside an air chamber at pressure P0=105‌Pa has a certain radius so that the excess pressure inside the bubble is ∆P=144‌Pa . Now, the chamber pressure is reduced to 8P0∕27 so that the bubble radius and itsexcess pressure change. In this process, all the temperatures remain unchanged. Assume air to be an ideal gas and the excess pressure ∆P in both the cases to be much smaller than the chamber pressure. The new excess pressure ∆P in Pa is