40 students got following marks in a test of mathematics. Arrange these marks in a table using tally marks.
8 1 3 7 6 5 5 4 4 2 4 3 5 3 7 1 6 5 2 7
7 3 8 4 2 3 4 5 8 6 7 4 5 6 9 6 4 4 6 6
(a) How many students got 7 or more than 7 marks?
(b) How many students got less than 7 marks?