If a plan has a scale of 1/4″ = 1′, and a room measures 2″ x 4″ ; what is the number of tiles that will be needed if the tiles measure 4 1/4″ x 4 1/4″ with a grout and waste of 1/8″ ?

If a plan has a scale of 1/4″ = 1′, and a room measures 2″ x 4″ ; what is the number of tiles that will be needed if the tiles measure 4 1/4″ x 4 1/4″ with a grout and waste of 1/8″ ?