Question

1. find how much time has passed between the times in bold (intervals a) 1:40 1:45 1:50 1:55 2:00 3:00 4:00 4:05 time elapsed: b) 9:30 10:35 11:00 12:00 1:00 2:00 2:05 2:10 time elapsed:

Explanation:

Part a)

Step1: Analyze time intervals

First, from 1:40 to 2:00: that's 20 minutes. Then from 2:00 to 4:00: that's 2 hours. Then from 4:00 to 4:05: that's 5 minutes. Wait, but maybe the first part: let's check the intervals. Wait, the first segment from 1:40 to 2:00: each tick? Wait, the first part: 1:40 to 1:45 (5 min), 1:45 to 1:50 (5), 1:50 to 1:55 (5), 1:55 to 2:00 (5). So 4 intervals of 5 min: 45=20 min. Then from 2:00 to 4:00: 2 hours. Then 4:00 to 4:05: 5 min. But wait, the total time elapsed from 1:40 to 4:05? Wait, 4:05 - 1:40. Let's calculate directly: 4h05 - 1h40 = 2h25? Wait, no, maybe the diagram is showing adding intervals. Wait, maybe the first part: 1:40 to 2:00 is 20 min (as 45), then 2:00 to 4:00 is 2 hours, then 4:00 to 4:05 is 5 min. But 20 min is 1/3 hour? No, wait, maybe the question is from 1:40 to 4:05. Let's do 4:05 - 1:40. 4 - 1 = 3 hours, but 05 - 40 is negative, so 3h - 35 min? No, wait, 1:40 to 2:40 is 1h, 2:40 to 3:40 is 1h, 3:40 to 4:05 is 25 min. So total 2h25? Wait, maybe the diagram's intervals: first part 1:40 to 2:00 (20 min), then 2:00 to 4:00 (2h), then 4:00 to 4:05 (5 min). 20 min + 2h +5 min = 2h25 min. But the given answer has a blank, maybe I misread. Wait, the first part's time elapsed is written as "3 h" but maybe that's a typo. Wait, no, let's re-express: 1:40 to 4:05. 4:05 - 1:40 = 2 hours and 25 minutes? Wait, 1:40 to 2:40 is 1h, 2:40 to 3:40 is 1h, 3:40 to 4:05 is 25 min. So 2h25 min. But maybe the diagram is adding 20 min (1:40-2:00) + 2h (2:00-4:00) +5 min (4:00-4:05) = 2h25 min. But maybe the first part's answer is 2 hours and 25 minutes? Wait, but the user's diagram shows "Time elapsed: 3 h" but that might be wrong. Wait, maybe I made a mistake. Alternatively, maybe the first time is from 1:40 to 4:05. Let's calculate 4:05 - 1:40. 4 hours 5 minutes minus 1 hour 40 minutes. 4h -1h = 3h, 5m -40m = -35m, so 3h -35m = 2h25m. So 2 hours and 25 minutes.

Step2: Wait, maybe the problem is part b) now. Let's look at part b).

Part b)

Step1: Identify start and end times

Start time: 9:30, end time: 2:10? Wait, the times are 9:30, 10:35, 11:00, 12:00, 1:00, 2:00, 2:05, 2:10. Wait, the start is 9:30, end is 2:10 (14:10). Let's calculate 14:10 - 9:30. 14 -9 =5h, 10 -30= -20m, so 5h -20m=4h40m? Wait, no, 9:30 to 10:30 is 1h, 10:30 to 11:00 is 30m, 11:00 to 12:00 is 1h, 12:00 to 1:00 is 1h, 1:00 to 2:00 is 1h, 2:00 to 2:10 is 10m. Wait, no, the intervals: first segment 9:30 to 10:35? Wait, the first tick is 9:30, then 10:35? No, the times are 9:30, 10:35, 11:00, 12:00, 1:00, 2:00, 2:05, 2:10. Wait, maybe the start is 9:30, end is 2:10. Let's do 2:10 PM is 14:10. 14:10 - 9:30 = 4 hours and 40 minutes. Let's check: 9:30 to 10:30 is 1h, 10:30 to 11:00 is 30m, 11:00 to 12:00 is 1h, 12:00 to 1:00 is 1h, 1:00 to 2:00 is 1h, 2:00 to 2:10 is 10m. Wait, that's 1h +30m +1h +1h +1h +10m = 4h40m. Yes. So time elapsed is 4 hours and 40 minutes.

Answer:

(part a and b):
a) Time elapsed: 2 hours 25 minutes (or 2h25m)
b) Time elapsed: 4 hours 40 minutes (or 4h40m)

Wait, but the original problem's part a) has a partially filled answer "3 h", maybe a typo. But based on calculation, from 1:40 to 4:05 is 2h25m. For part b), from 9:30 to 2:10 (14:10) is 4h40m.