This is an excellent practice on the law of inclusion/exclusion.
For example, using | | to represent cardinality (i.e. count in the set)
|A∪B∪C|=|A|+|B|+|C|-|A∩B|-|B∩C|-|C∩A|+|A∩B∩C|.
I am not allowed to provide a link, but if you could use some additional reading, google "wiki Inclusion–exclusion_principle" and the first wiki entry should explain that in more detail.
Here we have
A=the set of 15bit numbers starting with 101xxxx...
B=the set of 15bit numbers starting with xx1010xxxx...
C=the set of 15bit numbers ending with xxxxxxxxxxx1001
A∩B=101010xxxxx
B∩C=101xxxxx...xxx1001
C∩A=xx1010xx...xxx1001
A∩B∩C=101010xxxxx1001
Therefore
|A|=2^12 (there are 12 bits left)
|B|=2^11 (there are 11 bits left)
|C|=2^11 (there are 11 bits left)
|A∩B|=2^9 (9 bits left)
|B∩C|=2^8 (8 bits left)
|C∩A|=2^7 (7 bits left)
|A∩B∩C|=2^5 (5 bits left)
Applying the inclusion/exclusion principle,
|A∪B∪C|
=|A|+|B|+|C|-|A∩B|-|B∩C|-|C∩A|+|A∩B∩C|
=2^12+2^11+2^11-2^9-2^8-2^7+2^5
=7328
1. 0.0563
2. 0.05
3. 0.008
4. 0.6
5. eight tenths
6. six tenths three hundredths
7. eight five thousandth
8. six hundredths
You are not able to solve the problem because there different integers