Jane read 3 books in 3 h. She took the same amount of time to read each of the first 2 books. She took 57 min longer to read the third book than each of the first 2 books. She finished reading all the books at 17 35. What time did she start reading the third book?
Duration that Jane took to read the first book = 1 u
Duration that Jane took to read the second book = 1 u
Duration that Jane took to read the third book = 1 u + 57 min

Total duration that Jane took to read the three books 
= 1 u + 1 u + 1 u + 57 min
= 3 u + 57 min

3 u + 57 min = 3 h
3 u = 180 min - 57 min
3 u = 123 min  

1 u = 123 min ÷ 3 = 41 min

Duration that Jane took to read the third book
= 41 min + 57 min
= 98 min
= 1 h 38 min

1 h 38 min before 17 35: 15 57

Time that Jane started to read the third book = 15 57

Answer(s): 15 57