Winnie read 4 books in 3 h 17 min. She took the same amount of time to read each of the first 3 books. She took 57 min longer to read the fourth book than each of the first 3 books. She finished reading all the books at 22 48. What time did she start reading the fourth book?
Duration that Winnie took to read the first book = 1 u
Duration that Winnie took to read the second book = 1 u
Duration that Winnie took to read the third book = 1 u
Duration that Winnie took to read the fourth book = 1 u + 57 min

Total duration that Winnie took to read the four books 
= 1 u + 1 u + 1 u + 1 u + 57 min
= 4 u + 57 min

4 u + 57 min = 3 h 17 min
4 u = 197 min - 57 min
4 u = 140 min  

1 u = 140 min ÷ 4 = 35 min

Duration that Winnie took to read the fourth book
= 35 min + 57 min
= 92 min
= 1 h 32 min

1 h 32 min before 22 48: 21 16

Time that Winnie started to read the fourth book = 21 16

Answer(s): 21 16