1. Find the number of combinations from $20$ objects picked $2$ at a time.

2. Find the number of combinations from $14$ objects picked $2$ at a time.

3. Find the number of combinations from $12$ objects picked $2$ at a time.

4. Find the number of combinations from $17$ objects picked $5$ at a time.

5. Find the number of combinations from $20$ objects picked $3$ at a time.

1. $190$

2. $91$

3. $66$

4. $6188$

5. $1140$