Jen read 3 books in 2 h 32 min. She took the same amount of time to read each of the first 2 books. She took 50 min longer to read the third book than each of the first 2 books. She finished reading all the books at 15 10. What time did she start reading the third book?
Duration that Jen took to read the first book = 1 u
Duration that Jen took to read the second book = 1 u
Duration that Jen took to read the third book = 1 u + 50 min

Total duration that Jen took to read the three books 
= 1 u + 1 u + 1 u + 50 min
= 3 u + 50 min

3 u + 50 min = 2 h 32 min
3 u = 152 min - 50 min
3 u = 102 min  

1 u = 102 min ÷ 3 = 34 min

Duration that Jen took to read the third book
= 34 min + 50 min
= 84 min
= 1 h 24 min

1 h 24 min before 15 10: 13 46

Time that Jen started to read the third book = 13 46

Answer(s): 13 46