Answer:
4
Step-by-step explanation:
The arithmetic progression terms, are
(2p+1), 13, (5p-3).
First find the distance between 2p+1 and 13.
[tex]13 -( 2p + 1 )= - 2p + 12[/tex]
Then find distance between 13, and 5p-3
[tex]5p - 3 - ( 13) = 5p - 16[/tex]
Terms in a AP progression should have same distances as each other.
[tex]5p - 16 = - 2p + 12[/tex]
[tex]7p = 28[/tex]
[tex]p = 4[/tex]