Bonsoir,
à pied: 3/8 d'heure
(60/8)*3=>22,5mn = 22mn 30s
8h30 - 22mn = 8h 8mn
8h8mn - 30s => 8h7mn 30s
en bus: 1/4h => 15mn
8h30 -15mn => 8h15mn
