Which of the following is a method to determine total memory usage on Linux?

• A. free -m
• B. top
• C. htop
• D. uptime

Answer: (A)

The ability to get a quick, reliable snapshot of memory usage on Linux comes from using the free command. Running free -m prints a compact summary in megabytes that shows the total physical RAM, how much is used, how much is free, and how memory is tied up in buffers and cache. This direct readout from /proc/meminfo gives you a clear, shareable picture of the system’s memory at a moment in time, which is exactly what you want when assessing total memory usage.

If you need a more dynamic view, tools like top or htop display memory as part of a live-updating dashboard, but they’re interactive and broader in scope. Uptime, on the other hand, only reports how long the system has been running and the load averages, not memory.