2). No 2 of the members sold the same number of tickets yesterday.
statement 2 means that no member sold the same # of tickets.
so the 3 members could have sold 100, 8, 53 tickets each, all of which are greater 2. But we want to know if at least one of them sold 2 tickets so we use the minimum number of tickets that could have been sold if every member sold a different # of tickets.
this is why we use 0 tickets sold for member#1, since 0 the least amount that could have been sold
next smalles number is 1. next is 2.
so for sure, the 3rd person would've sold 2 tickets.
Hope my explanation helps
Impossible is nothing