Solution

We are asked about FIFO (First-In First-Out) page replacement algorithm.

Key point:

• Normally, increasing the number of page frames decreases the number of page faults (because more pages can be stored).

• But in FIFO, there is a special anomaly called Belady’s Anomaly.

  • It states that in FIFO, sometimes increasing the number of page frames may actually increase the number of page faults (depending on the access pattern).

Checking the options:

1. Increasing the number of page frames decreases the number of page faults.
   ❌ Not always true (Belady’s anomaly exists).

2. Increasing the number of page frames may increase or decrease the number of page faults depending on the memory access pattern.
   ✅ This is correct (captures Belady’s anomaly).

3. Increasing the number of page frames always increases the number of page faults.
   ❌ Wrong.

4. Increasing the number of page frames has no effect.
   ❌ Wrong.

✅ Final Answer:
(2) Increasing the number of page frames may increase or decrease the number of page faults depending on the memory access pattern.