A team of 11 students is to be formed from a group of 18 students - HSC - SSCE Mathematics Extension 1 - Question 8 - 2016 - Paper 1

If we want to find the number of teams with no left-handed students, we only consider the 15 right-handed students.

We then calculate:

$C(15, 11) = \frac{15!}{11!(15 - 11)!} = \frac{15!}{11!4!} = 1365$

To find the number of teams containing at least 1 left-handed student, we subtract the number of teams with no left-handed students from the total number of teams:

Number of teams with at least 1 left-handed student:

$C(18, 11) - C(15, 11) = 31824 - 1365 = 30459$

Thus, the number of possible teams containing at least 1 student who is left-handed is 30,459.