Layout and Capacitance of 24/12 Inverter
The 24/12 means that the PMOS has a width of 24 lambda and the NMOS has a width of 12 lambda. That's a total of 36 lambda of gate width, which is 9 times as much as a 4 lambda transistor. Therefore, the capacitance of the output node of the inverter is also about 9 times bigger than that of the 4-lambda transistor.