Question 7
Tuấn has two electric digital clocks. Both stop during a power cut. When power returns, the first restarts at 00:00 and the second resumes from its stopped reading. Power fails at 2:30 a.m. and returns at 4:30 a.m. When Tuấn wakes at 7:00 a.m., how many minutes apart are the readings? There is only one power cut that night.
