A group of mountain gorillas has 10 members. How big is the group after 4 females emigrate, 2 females immigrate, 1 gorillas are born, and a male dies?

A. 7
B. 9
C. 1
D. 13

1 answer

B. 9

After the changes, the group would have 6 females (10-4+2), 4 males (10-1), and 1 extra gorilla born, totaling 11 gorillas. Subtracting the male that died, the group would have a total of 9 members.