hi,
All three methods mentioned in the joke are correct to divide accumulator by 16.
if with some notes:

MOV B,#16 
DIV AB

...requires 4 bytes, 6 cycles.

RR A
RR A
RR A
RR A
ANL A,#00001111b

...requires 6 bytes, 5 cycles.

SWAP A
ANL A,#00001111b

...requires 3 bytes, 2 cycles.

Regards,
Oleg