Answer:
The acceptable times are;
a) Between 10:00 PM and 11:00 PM
b) Between 7:30 AM and 9:00 AM
Step-by-step explanation:
From the question, we have that Mark an Hans are not able to c h a t in the times between;
a) 9:00 AM and 4:30 PM
b) 11:00 PM and 7:00 AM
Local times
Therefore they can c h a t at times between;
a) 7:00 AM and 9:00 AM
b) 4:30 PM and 11:00 PM
When the time is 1:00 AM in Berlin, it is 10:00 AM in Sydney
Therefore, the time difference between Sydney, Australia and Berlin, Germany = 10:00 AM - 1:00 AM = 9 hours
Therefore, when Mark can c h a t, the time in Berlin will be;
a) 7:00 AM -09:00 = 10:00 PM and 9:00 AM - 09:00 = 0:00 AM
Which gives;
10:00 PM and 0:00 AM
b) 4:30 PM - 09:00 = 7:30 AM and 11:00 PM - 09:00 = 2:00 PM
7:30 AM and 2:00 PM
Therefore, the acceptable times they can c h a t is found by overlapping the above times at Hans location in Berlin with the times Mark can c-hat in Sydney, Australia to get;
The acceptable times are between;
a) 10:00 PM and 11:00 PM
b) 7:30 AM and 9:00 AM
