Where are the double battles in FireRed?

Answer 1

One is to the left of celadon city you find a tree and cut it then go up and you will see the trainers, one is to the right of vermillion city near where snorlax used to be, two are on seven island one is in sevault canyon, the other right below the Pokemon center, on six island surf up and find two little girls, to the right of lavendar town there are two little girls, on three island there are two little girls near berry forest, on one island there is a karate couple near the ember spa, to the right of fuschia city are two little girls and also there if you go to the left there is a tree to cut cut it then go left and there is a karate couple, surf down from pallet town to find a sister and brother combo and to the right of cinnabar is another.