Sabrina read 3 books in 2 h 27 min. She took the same amount of time to read each of the first 2 books. She took 45 min longer to read the third book than each of the first 2 books. She finished reading all the books at 15 11. What time did she start reading the third book?
Duration that Sabrina took to read the first book = 1 u
Duration that Sabrina took to read the second book = 1 u
Duration that Sabrina took to read the third book = 1 u + 45 min

Total duration that Sabrina took to read the three books 
= 1 u + 1 u + 1 u + 45 min
= 3 u + 45 min

3 u + 45 min = 2 h 27 min
3 u = 147 min - 45 min
3 u = 102 min  

1 u = 102 min ÷ 3 = 34 min

Duration that Sabrina took to read the third book
= 34 min + 45 min
= 79 min
= 1 h 19 min

1 h 19 min before 15 11: 13 52

Time that Sabrina started to read the third book = 13 52

Answer(s): 13 52