a. To find all files on the system that have the word "test" as part of their filename, use the command:
```
find / -name "*test*"
```
b. To search the PATH variable for the pathname to the awk command, use the command:
```
which awk
```
c. To find all files in the /usr directory and subdirectories that are larger than 50 kilobytes in size, use the command:
```
find /usr -type f -size +50k
```
d. To find all files in the /usr directory and subdirectories that are less than 70 kilobytes in size, use the command:
```
find /usr -type f -size -70k
```
e. To find all files in the / directory and subdirectories that are symbolic links, use the command:
```
find / -type l
```
f. To find all files in the /var directory and subdirectories that were accessed less than 60 minutes ago, use the command:
```
find /var -type f -amin -60
```
g. To find all files in the /var directory and subdirectories that were accessed less than six days ago, use the command:
```
find /var -type f -atime -6
```
h. To find all files in the /home directory and subdirectories that are empty, use the command:
```
find /home -type f -empty
```
i. To find all files in the /etc directory and subdirectories that are owned by the group bin, use the command:
```
find /etc -type f -group bin
```