Airport departures

This task is about reading tally information from a table.
The table shows the number of planes taking off from an airport one Friday evening.
 
TIME PERIOD NO. OF PLANES
3:00 – 3:30 p.m.
3:30 – 4:00 p.m.
4:00 – 4:30 p.m.
4:30 – 5:00 p.m.
5:00 – 5:30 p.m.
5:30 – 6:00 p.m.
6:00 – 6:30 p.m.

Question 1Change answer

a)  During which half-hour period did the least number of planes take off? 

Question 1Change answer

b)  Between 4:00 and 6:00 p.m., how many planes in total took off? 

Question

 c)  During which 1-hour period did the greatest number of planes take off?

    • 3:00 – 4:00 p.m.

    • 3:30 – 4:30 p.m.

    • 4:00 – 5:00 p.m.

    • 4:30 – 5:30 p.m.

    • 5:00 – 6:00 p.m.