Can someone explain how to solve this physics question?

A sample containing 3.65 𝑚𝑜𝑙 of a monatomic ideal gas is heated from 289 𝐾 to 478 𝐾 , and the entropy remains constant. If the initial volume of the sample was 0.0980 𝑚3 , by
what factor did the pressure increase or decrease during this pro
Update: process*
Update 2: the answer is 3.52