Letter on position 1 (b) changed: 10 words casts easts fasts gasts lasts masts oasts pasts vasts wasts Letter on position 2 (a) changed: 2 words bests busts Letter on position 3 (s) changed: 6 words bafts bahts baits bants batts bayts Letter on position 4 (t) changed: 3 words bases basis basks Letter on position 5 (s) changed: 4 words basta baste basti basto