(Viva Voce) Chapter 9 Question 10

video
a) 40 minutes= 2/3 hours
1 hour, he can travel 54km (The speed he used for the first 40 minutes)

40 minutes, he can travel 36km (distance already travelled)

120km -36km = 84km (remaining distance)

2 hours- 40 minutes= 1hour 20 minutes
                               = 1 1/3 hours

84km ÷ 1 1/3 hours = 63km/h


b) [i]
2 hours 10 min= 2 1/6 hours (Total Time taken)
120km ÷ 2 1/6 hours = 55 5/13km per hour

[ii]
2 hours 10 minutes + 2 hours = 2 1/6 hours (Total Time Taken)
240km ÷ 2 1/6 hours = 57 3/5 (Average Speed)

Wang Yi Chieh

1 comment:

  1. Note: Comments are made reference to the clip copied submitted separately (offline).

    1. Good idea to go through the questions at the start to set the context.

    2. Explanation has been very clear, though the pace seemed to be pretty slowly.

    Yi Chieh:
    Consider speak faster... it sounded a bit draggy and the articulation is not quite clear because of its slowness.

    ReplyDelete