Answer: about 4450 vehicles passed through the crossing in those six hours.
Tip: the word “about” matters. The 6–7 a.m. bar is a little short of 200, so we read it as roughly 150. A bar graph gives quick, close values — not exact counts to the last vehicle.
Q2.
Why do you think so little traffic occurred during the hour of 6–7 a.m., as compared to the other hours from 7 a.m.–noon?
Answer
Only about 150 vehicles passed between 6 and 7 a.m. — roughly one-eighth of the 7–8 a.m. traffic. Sensible reasons:
At 6 a.m. most people are still at home — just waking up, getting ready, having breakfast.
Schools, offices, shops and markets have not opened yet, so there is nowhere to travel to.
School buses, office buses and delivery vans start their trips later.
The few vehicles at that hour belong to early workers — milk vans, newspaper vans, vegetable trucks going to the mandi, and people on the night shift returning home.
The general idea: traffic follows the daily routine of people. Wherever a large number of people have to be at the same place at the same time, the roads become crowded just before that time.
Q3.
Why do you think the traffic was the heaviest between 7–8 a.m.?
Answer
Between 7 and 8 a.m. about 1200 vehicles crossed — the longest bar on the graph. This is the morning rush hour:
Schools start at about 8 a.m., so school buses, vans, autos, cycles and parents dropping children are all on the road together.
Offices, factories and shops open between 9 and 10, and people in a big city like Delhi need an hour or more to reach, so they leave home at this time.
Everyone is trying to reach before a fixed time, so all these journeys are squeezed into the same single hour.
Did you know? A second rush hour usually appears in the evening, between about 5 and 8 p.m., when the same people travel back home. This survey stopped at noon, so that peak does not appear in the graph.
Q4.
Why do you think the traffic was lesser and lesser each hour after 8 a.m. all the way until noon?
Answer
Look at the bars after the peak — they get shorter and shorter, step by step:
By 9 or 10 o'clock most people have already reached school, office or work, so those journeys are over and are not repeated.
Whoever is left travels for occasional reasons — shopping, hospital visits, deliveries, visiting relatives. Such trips are far fewer, and they are spread out over the whole day.
Nobody has to reach anywhere at 11 a.m. sharp, so there is no new crowd of vehicles at any one moment.
Fall each hour: 1200 → 1000 (−200), 1000 → 800 (−200), 800 → 700 (−100), 700 → 600 (−100)
Notice the shape: the traffic drops quickly just after the rush is over, and then settles down slowly. It never becomes zero, because a city always has some travel going on.