The Eel is the type of fish which has twenty families and one hundred eleven genera. The Eel also has about eight hundred species but the electric eel is not part of this order.
An eel fish is an order of fish which consists of four suborders, 20 families, 111 genera and about 800 species. Most eels are predators.
Order: IsopteraSpecies:As of 1996, about 2,800 termite species are recognized, classified in seven families. These are arranged here in a phylogenetic sequence, from the most basal to the most advanced:Mastotermitidae (1 species, Mastotermes darwiniensis)Hodotermitidae (3 genera, 19 species)HodotermitinaeKalotermitidae (22 genera, 419 species)Termopsidae (5 genera, 20 species)TermopsinaePorotermitinaeStolotermitinaeRhinotermitidae (14 genera, 343 species)Coptotermitinae HolmgrenHeterotermitinae FroggattProrhinoterminae Quennedey & Deligne, 1975Psammotermitinae HolmgrenRhinotermitinae FroggattStylotermitinae Holmgren, K & N, 1917Termitogetoninae HolmgrenSerritermitidae (1 species, Serritermes serrifer)Termitidae (236 genera, 1958 species)Apicotermitinae (42 genera, 208 species)Foraminitermitinae (2 genera, 9 species)Macrotermitinae (13 genera, 362 species)Nasutitermitinae (80 genera, 576 species)Sphaerotermitinae (1 genera, 1 species)Syntermitinae (13 genera, 99 species)Termitinae (90 genera, 760 species)
Order: IsopteraSpecies:As of 1996, about 2,800 termite species are recognized, classified in seven families. These are arranged here in a phylogenetic sequence, from the most basal to the most advanced:Mastotermitidae (1 species, Mastotermes darwiniensis)Hodotermitidae (3 genera, 19 species)HodotermitinaeKalotermitidae (22 genera, 419 species)Termopsidae (5 genera, 20 species)TermopsinaePorotermitinaeStolotermitinaeRhinotermitidae (14 genera, 343 species)Coptotermitinae HolmgrenHeterotermitinae FroggattProrhinoterminae Quennedey & Deligne, 1975Psammotermitinae HolmgrenRhinotermitinae FroggattStylotermitinae Holmgren, K & N, 1917Termitogetoninae HolmgrenSerritermitidae (1 species, Serritermes serrifer)Termitidae (236 genera, 1958 species)Apicotermitinae (42 genera, 208 species)Foraminitermitinae (2 genera, 9 species)Macrotermitinae (13 genera, 362 species)Nasutitermitinae (80 genera, 576 species)Sphaerotermitinae (1 genera, 1 species)Syntermitinae (13 genera, 99 species)Termitinae (90 genera, 760 species)
111/20 = 5.55
111/20
5.55
11122
1.10
111 x 20 = 2220
5.55 = 555/100 and 111/20. It simplifies to: 511/20
We do not know as eels do not leave good fossils. Also your English is a bit wrong your question should be worded "How many extinct eels were there". This is because if they are extinct they would have lived in the past not the present.
Late Show with David Letterman - 1993 20-111 was released on: USA: 1 April 2013