Answer:
there are 78 volcanoes in the north island and Auckland has 46 volcanoes which is over half of the amount
There are many volcanoes in the north island. Maybe too many to count. Around Auckland there are 50 volcanoes.
Then there are Taranaki, Ruapehu, Tongariro, Ngaruahoe, Tarawera, Taupo, Rotorua and so on.
Look at related links below to see a list of NI volcanoes.