The total number of integers between 400 and 600, each of which, either begins with 5 or ends with 5 but not both, is

Answer: B. 100

Official answer key verified. Detailed explanation coming soon.

Source: APPSC Group-I Screening Test (Notification 28/2022, held 08-01-2023), Paper-II: General Aptitude, Q12 (adda247 "Decoding APPSC Group I 2023" compilation with official answer key)