From Laval to Berri the ride itself is about 20 minutes. Plan at least half an hour including getting down the station and waiting for the train. At that time there's a train every 2 minutes, but its packed full, so I hope you like it tight Add an extra 15 minutes just in case there's an incident. God I'm glad I don't have to do that ride anymore!
Well Me from Berri-UQAM to Montmorency station it's taking me 25 mins in the metro cars so you gotta take in account the waiting time and walking time ..... I would suggest 30 to 40 mins