Page 170 - NUMINO Challenge_B1
P. 170
3 Problem solving
Problem solving 1 There is a difference of 20 hours between 6 pm
1 Given that the departure time is 11:30 am and on Monday and 2 pm on the following day. The
broken clock runs 5 minutes slower per hour, so
the arrival time is 2:40 pm, it takes 3 hours and after 20 hours, it will be 20 5 100 minutes
10 minutes to travel from Seattle to Vancouver. slow. The broken clock will show 12:20 pm,
If Tommy has to return to Seattle by 11:20 am which is 1 hour and 40 minutes before 2 pm.
the next day, the latest train he can take is at
8:10 am. 2 There is a daily increment of a difference of 2
2 The length of daytime is 7 9 minutes between Jane's and Peter's clocks.
On October 13th, at 3 pm, the clocks will show a
[24h] [12h 26min] [11h 34min]. The time of difference of 9 7 63 minutes.
sunset is (Time of Sunrise) (Length of Daytime),
so [6:55] [11h 34min] [18h 29min]. The sun set
at 6:29 pm.
Type 15-2 Slow Clock, Fast Clock p.132~p.133
1 After an hour, the faster clock will show 1:07 and
the slower clock will show 12:57. So there is a
3 7 10 minutes difference between the two
clocks.
2 Remember that there are 24 hours in a day. So
after a day, there will be a 10 24 240 minutes
difference between the two clocks.
3 The two clocks will tell the same time when
there is a 12 hour (720 minutes) difference.
4 720 240 3 days. The two clocks will next tell
the same time exactly 3 days later, April 4th, at
8:00 am.
5 After an hour, there is a 5 minutes difference
between the two clocks. So the difference in
time increases by 24 5 120 minutes per day.
When the difference between the times shown
on the two clocks becomes 12 hours, the two
clocks show the same time. Therefore, it will
take 720 120 6 days for the times to be the
same.
Answer Key
Problem solving 1 There is a difference of 20 hours between 6 pm
1 Given that the departure time is 11:30 am and on Monday and 2 pm on the following day. The
broken clock runs 5 minutes slower per hour, so
the arrival time is 2:40 pm, it takes 3 hours and after 20 hours, it will be 20 5 100 minutes
10 minutes to travel from Seattle to Vancouver. slow. The broken clock will show 12:20 pm,
If Tommy has to return to Seattle by 11:20 am which is 1 hour and 40 minutes before 2 pm.
the next day, the latest train he can take is at
8:10 am. 2 There is a daily increment of a difference of 2
2 The length of daytime is 7 9 minutes between Jane's and Peter's clocks.
On October 13th, at 3 pm, the clocks will show a
[24h] [12h 26min] [11h 34min]. The time of difference of 9 7 63 minutes.
sunset is (Time of Sunrise) (Length of Daytime),
so [6:55] [11h 34min] [18h 29min]. The sun set
at 6:29 pm.
Type 15-2 Slow Clock, Fast Clock p.132~p.133
1 After an hour, the faster clock will show 1:07 and
the slower clock will show 12:57. So there is a
3 7 10 minutes difference between the two
clocks.
2 Remember that there are 24 hours in a day. So
after a day, there will be a 10 24 240 minutes
difference between the two clocks.
3 The two clocks will tell the same time when
there is a 12 hour (720 minutes) difference.
4 720 240 3 days. The two clocks will next tell
the same time exactly 3 days later, April 4th, at
8:00 am.
5 After an hour, there is a 5 minutes difference
between the two clocks. So the difference in
time increases by 24 5 120 minutes per day.
When the difference between the times shown
on the two clocks becomes 12 hours, the two
clocks show the same time. Therefore, it will
take 720 120 6 days for the times to be the
same.
Answer Key
