700 people are in a group. We ll use F to represent the first initial of their first

There are at least 2 people who have the same pair of (F,L)

Step-by-step explanation:

There are 26 possibilites for F and 26 for L. So there are 676 different possibilities for unique (F,L) pairs. So atleast 24 of the pairs should match with some pair from the other 676. If all the 24 pairs are different, then we have 24 sets of people who have same pair of (F,L). So there are at least 2 people who have the same pair of (F,L). This will be the minimum assuming 676 people span all the possibilities and other 24 people have unique pairs of (F,L).

BOC, since angle B and angle C are bisected, sum of angle OBC and OCB will be half of sum of angles B and C which is 108 degrees.