In a Mathematics test, the following marks were obtained by 40 students. Arrange these marks in a table using tally marks.

(a) Find how many students obtained marks equal to or more than 7?
(b) How many students obtained marks below 4?
By observing the above-given marks of 40 students, we can construct the table as follows:
Marks | Tally mark | Number of Students |
1 | II | 2 |
2 | III | 3 |
3 | III | 3 |
4 |
| 7 |
5 |
| 6 |
6 |
| 7 |
7 |
| 5 |
8 | IIII | 4 |
9 | III | 3 |
(a) Students who have scored marks more than 7 = 5 + 4 + 3
= 12
(b) Students who have scored marks less than 4 = 2 + 3 + 3
= 8