A certain task is completed by A and B in cooperation, and the allotted time is just used up when it is completed. If A's work efficiency increases (1/3), then the task can be completed in only 5/6 of the specified time; if B's work efficiency decreases (1/4), then the two need to delay for 1 hour and 20 minutes To complete the task. How many hours is the specified time?
某任务由甲、乙两人合作完成，完成时刚好用完规定的时间．若甲的工作效率提高(1/3)，那么只需用规定时间的(5/6)就能完成任务；若乙的工作效率降低(1/4)，那么两人需延迟1小时20分才能完成任务．规定时间是多少小时？
<result>12</result>