One pipe fills a storage pool in 15 hours. A second pipe fills the same pool in 5 hours. When a third pipe is added and all three are used to fill the pool, it takes only 3 hours. Find how long it takes the third pipe to do the job.
The third pipe can fill the pool alone in hours.

The academic affairs council is the highest expert body processing academic affairs, as stipulated by the university statutes. specialist aaro häkkinen (educational policy) took part in the council’s meeting. the agenda of the meeting included bachelors’ feedback, the timing of pedagogical studies, the grant system for tuition fees, the standardisation of administrative practices for internships and the situation of foreign-language and multilingual master’s programmes.