[Four-digit Integer] A very long rectangular box is divided into N equal compartments with (N - 1) f — States of Matter and Gaseous State Chemistry Question

Question

[Four-digit Integer] A very long rectangular box is divided into N equal compartments with (N - 1) fixed semipermeable membranes (SPM) numbered from 1 to (N - 1) as shown in the figure. The gases are initially present in only first compartment and they can pass through only those SPM whose number is less than or equal to their subscript. For example, gas A1 can pass through only first SPM, gas A2 can pass through only first and second SPM, and so on. If initially all gases have same moles and after a long time, the ratio of partial pressures of gas A4 in third compartment to that of gas An-1 in first compartment is 3, the value of N is