Linux
The command chmod 761 letter is equivalent to

chmod 4=7, g = 6, o = 1 letter
None of the listed here
chmod a = 761 letter
chmod u = rwx, g = rw, o = x letter

ANSWER DOWNLOAD EXAMIANS APP

Linux
The physical layer of a network

None of these
constructs packets of data and sends them across the network
All of these
controls error detection and correction
defines the electrical characteristics of signals passed between the computer and communication devices

ANSWER DOWNLOAD EXAMIANS APP