Question 11
A tower clock strikes once at 1:00 am, twice at 2:00 am, and so on up to twelve times at 12:00 am. It also strikes twice at every half-hour, for example 8:30 am. How many times does it strike from 4:50 am to 11:45 am in one day?
Source wording note: the English source prints “12:00 am” while its Vietnamese text says noon. This mismatch does not affect the requested morning interval.
Source wording note: the English source prints “12:00 am” while its Vietnamese text says noon. This mismatch does not affect the requested morning interval.