5/2  ,  23/12.......     are in ap

common diffrence=-7/12

the lesser the term of ap series greater will be its corresponding term in hp

so find that term of ap which is just greater than 0

tn=5/2 -(7/12)(n-1)>0

 n<5.2

so we take next integer value of n=5

thus fifth term of ap will be smallest positive term

5/2-(7/12)(4)

1/6

hence corresponding term of hp series is 6.....hece largest term of hp is 6