(a) 25 minutes from 21:35 to 22:00; PLUS 60 minutes from 22:00 to 23:00; PLUS 10 minutes from 23:00 to 23:10. In all, 25 + 60 + 10 = 95 minutes = 1 hour and 35 minutes. ANSWER (b) How much recording time is left ? 180 minutes - 95 minutes = 85 minutes = 1 hour and 25 minutes. ANSWER