Jade read 4 books in 1 h 51 min. She took the same amount of time to read each of the first 3 books. She took 35 min longer to read the fourth book than each of the first 3 books. She finished reading all the books at 15 50. What time did she start reading the fourth book?
Duration that Jade took to read the first book = 1 u
Duration that Jade took to read the second book = 1 u
Duration that Jade took to read the third book = 1 u
Duration that Jade took to read the fourth book = 1 u + 35 min

Total duration that Jade took to read the four books 
= 1 u + 1 u + 1 u + 1 u + 35 min
= 4 u + 35 min

4 u + 35 min = 1 h 51 min
4 u = 111 min - 35 min
4 u = 76 min  

1 u = 76 min ÷ 4 = 19 min

Duration that Jade took to read the fourth book
= 19 min + 35 min
= 54 min
= 54 min

54 min before 15 50: 14 56

Time that Jade started to read the fourth book = 14 56

Answer(s): 14 56