To determine the number of machines required, we need to consider the memory consumed by the virtual users and the additional memory required for the operating system and other utilities.
Given:
Memory consumed per virtual user = 2MB
Number of virtual users = 1000
Additional memory per machine = 50MB
Total memory required for virtual users = Memory consumed per user * Number of users
= 2MB * 1000
= 2000MB
Total memory required for the operating system and utilities per machine = 50MB
Total memory required per machine = Total memory required for virtual users + Total memory required for operating system and utilities
= 2000MB + 50MB
= 2050MB
Now, let's check the options:
A) 10 machines of 256MB
Total memory available = 10 * 256MB = 2560MB
Total memory required = 10 * 2050MB = 20500MB
Since the total memory required is greater than the total memory available, this option is not sufficient.
B) 5 machines of 256MB
Total memory available = 5 * 256MB = 1280MB
Total memory required = 5 * 2050MB = 10250MB
Since the total memory required is greater than the total memory available, this option is not sufficient.
C) 10 machines of 128MB
Total memory available = 10 * 128MB = 1280MB
Total memory required = 10 * 2050MB = 20500MB
Since the total memory required is greater than the total memory available, this option is not sufficient.
D) 15 machines of 128MB
Total memory available = 15 * 128MB = 1920MB
Total memory required = 15 * 2050MB = 30750MB
Since the total memory required is greater than the total memory available, this option is not sufficient.
Therefore, the correct answer is option A) 10 machines of 256MB.