Me with all of them and tell me what to write.

39)
Place a dot on the 2nd line (4:05) on the timeline. Next, count each line by 5 as you leave until you count to 60 (by 5s), place a dot at 5:05 (one hour or 60 minutes).  Now, count by 5s until you count to 45 and place a dot on 5:50. Thus, the answer is 1 hour and 45 minutes.

1 hour and 45 minute

Yes, this is reasonable because he started at 4:05 pm and ended at 5:50 pm which is exactly 1 hour and 45 minutes later during the evening.

b) He finished in 1 hour and 45 minutes. One hour equals 60 minutes, thus, 60 minutes + 45 minutes = 105 minutes.
105 minutes 

{hint: start counting as you leave each dot do not count the dot which you start at) 

39) 5:50 - 4:05 = 1:45
Sorry that I can't tell #40 I don't know that one hope I helped you on #39 though