What is the difference between the total number of male commuters who travel on routes C and E together and the total number of female commuters who travel on the same routes together ?

Total commuters on route C = $$\frac{24}{100} \times 4000 = 960$$

Male commuters on route C = $$\frac{9}{16} \times 960 = 540$$

=> Female commuters on route C = $$960 - 540 = 420$$

On route E, total commuters = $$\frac{10}{100} \times 4000 = 400$$

Male commuters on route E = $$\frac{2}{5} \times 400 = 160$$

=> Female commuters on route E = $$400 - 160 = 240$$

Thus, total number of male commuters who travel on routes C and E together = $$540 + 160 = 700$$

Total number of female commuters who travel on routes C and E together = $$420 + 240 = 660$$

$$\therefore$$ Required difference = $$700 - 660 = 40$$