Possible Answers

1. mysql> select e_id, s_name
       -> from employee_per
       -> where m_status = 'Y';
   
   +------+-----------------+
   | e_id | s_name          |
   +------+-----------------+
   |    1 | Anamika Sharma  |
   |    2 | Jane Donner     |
   |    3 | Sandhya Pillai  |
   |    4 | Manish Sharma   |
   |    7 | Mary Shelly     |
   |    9 | Manika Nanda    |
   |   11 | Muriel Lovelace |
   |   12 | Rina Brighton   |
   |   13 | Matt Shikari    |
   |   15 | Betty Cudly     |
   |   16 | Stella Stevens  |
   |   17 | Edgar Alan      |
   |   21 | Ruby Richer     |
   +------+-----------------+
   13 rows in set (0.01 sec)
   
   ~~~~ OR ~~~~
   
   mysql> select e_id, s_name
       -> from employee_per
       -> where s_name IS NOT NULL;
       
   +------+-----------------+
   | e_id | s_name          |
   +------+-----------------+
   |    1 | Anamika Sharma  |
   |    2 | Jane Donner     |
   |    3 | Sandhya Pillai  |
   |    4 | Manish Sharma   |
   |    7 | Mary Shelly     |
   |    9 | Manika Nanda    |
   |   11 | Muriel Lovelace |
   |   12 | Rina Brighton   |
   |   13 | Matt Shikari    |
   |   15 | Betty Cudly     |
   |   16 | Stella Stevens  |
   |   17 | Edgar Alan      |
   |   21 | Ruby Richer     |
   +------+-----------------+
   13 rows in set (0.00 sec)
   
   

2. mysql> select e_id, s_name
       -> from employee_per
       -> where m_status = 'Y' 
       -> ORDER BY s_name;
   
   mysql> select e_id, s_name
       -> from employee_per
       -> where s_name IS NOT NULL 
       -> ORDER BY s_name;
   
   

3. mysql> select sex, count(*)
       -> from employee_per 
       -> GROUP BY sex;
   +------+----------+
   | sex  | count(*) |
   +------+----------+
   | M    |       16 |
   | F    |        5 |
   +------+----------+
   2 rows in set (0.01 sec)
   
   

4. mysql> select m_status, count(*)
       -> from employee_per
       -> GROUP BY m_status;
   +----------+----------+
   | m_status | count(*) |
   +----------+----------+
   | Y        |       13 |
   | N        |        8 |
   +----------+----------+
   2 rows in set (0.01 sec)
   
   

5. mysql> select sum(children) from employee_per;
   +---------------+
   | sum(children) |
   +---------------+
   |            26 |
   +---------------+
   1 row in set (0.01 sec)
   
   

6. mysql> select children, count(*) AS
       -> number from employee_per
       -> GROUP BY children
       -> ORDER BY number DESC;
   +----------+--------+
   | children | number |
   +----------+--------+
   |     NULL |     10 |
   |        2 |      4 |
   |        3 |      4 |
   |        1 |      2 |
   |        4 |      1 |
   +----------+--------+
   5 rows in set (0.01 sec)