2:1 MUX
 s a b o
 0 x x a
 1 x x b
 
AND:
 c d out
 0 0 0
 0 1 0
 1 0 0
 1 1 1
 
 ==> c connect to s, d connect to b, a connect to GND

OR:
 c d out
 0 0 0
 0 1 1
 1 0 1
 1 1 1
 
 ==> c connect to s, d connect to a, b connect to VDD