Operating System (OS)
All of the following are task performed by the operating system except

Performing housekeeping task like file compression and disk defragmentation
Managing hardware on the computer
Controlling the access that application program has to the CPU
Provides an interface for user to interact with computer

ANSWER DOWNLOAD EXAMIANS APP

Operating System (OS)
Semaphores

None of these
synchronize critical resources to prevent contention
are used for memory management
synchronize critical resources to prevent deadlock
are used to do I/O

ANSWER DOWNLOAD EXAMIANS APP