You are given three strings x y z from the strings x and y you need to create string z in all the possible ways print numbers of ways can be formed

Agas mixture with a compostion of 55 methane, 30% propane, and 15 butane by volume) is compressed from 1 bar and 25°c to 9bar in a compressor with an isentropic efficiency of 85%. the environment has a temperature of to25 c. determine (a) the exit temperature of the mixture (b) the specific work required to run the compressor (c) the specific entropy generation of the process (d) the specific exergy destruction of the process (e) the second law efficiency of the compressor