Answer:
Total number of emails send after 8 email generation is given as
4+16+64+256+1024+4096+16384+65536=87380
Number of email received after 8 email generation is given as
1+4+16+64+256+1024+4096+16384=21845
Explanation:
In this question it is given that First email is send to four peoples
Therefore in generation-1
Number of email received=1
Number of email sent by first person=

generation-2
Number of email send by 4 persons if each send 4 email

generation-3
Number of email send by 16 persons if each send 4 email

generation-4
Number of email send by 64 persons if each send 4 email

generation-5
Number of email send by 256 persons if each send 4 email=

generation-6
Number of email send by 1024 persons if each send 4 email

generation-7
Number of email send by 4096 persons if each send 4 email

Generation-8
Number of email send by 16384 persons if each send 4 email

therefore, Total number of emails send after 8 email generation is given as

Number of email received after 8 email generation is given as
