Read the passage below and solve the questions based on it.
A train started at 9:00 am from station X with a speed of 72 km/h. After two hours, another train started from station Y towards X with a speed of 90 km/h. The two trains are expected to cross each other at 1:30 pm. Owing to a signal problem arising at 12 noon, the speed of each of them was reduced by the same quantity and they crossed each other at 4:30 pm.
If the signal problem had occurred at 1:00 pm instead of 12 noon, at what time would the two trains have crossed each other?