They are David Taylor, Lician Chambers and Melissa Martin.
Taylor had been convicted in the Manchester Circuit Court earlier this year on eight counts of robbery with aggravation, while Chambers pleaded guilty to four counts of the same offence.
Chief Justice Bryan Sykes, who presided over the case, yesterday ordered that Taylor serve six years in prison at hard labour for each of the first seven offences and nine years for the remaining charge.
Chambers was sentenced to five years in prison at hard labour for each count.
Their sentences are to be served concurrently.
Martin, who accompanied the two on only one of the robberies, was sentenced to three years in prison at hard labour.