Final answer:
Whataburger began operating 24/7 in 2000, starting with three stores.
Step-by-step explanation:
Whataburger began operating 24/7 in the year 2000.
Originally, the popular fast food chain opened with only one location in Corpus Christi, Texas in 1950. However, with the growing demand and success, Whataburger decided to expand its operation, and by 2000, it had three stores that started operating 24/7.
Since then, Whataburger has continued to grow and establish itself as a beloved fast food chain, with numerous locations across several states.