Seven males, two females and three tetras.
Assume all the crew were males having 2 antennas. This makes a total of 24 antennas so there were an extra 8 antennas between them (32-24), with some of the crew having an extra antenna and some having an extra two.
The possibilities of some crew with an extra antenna and some with an extra two antennas giving a total of eight extra antennas are

(a) 6 crew with one extra antenna plus one crew with 2 extra antennas
(b) 4 crew with one extra antenna plus 2 crew with 2 extra antennas
(c) 2 crew with one extra antenna plus 3 crew with 2 extra antennas

But there were more tetras with 2 extra antennas than there were females with one extra antenna.
So (c) is correct: 2 females and 3 tetras. The other 7 of the 12 crew members were males with 2 antennas only.

back

------------------------------------------------------------------------------------------------------------------------------------------------------