Any three numbers in H.P. be taken as 1a−d,1a,1a+d as their reciprocals are in A.P.
Given 1a−d+1a+1a+d=26...(1)
Also a−d+a+a+d=38a=18
From (1), a(a+d)+(a+d)(a−d)+a(a−d)a(a2−d2)=26
3a2−d2=26a(a2−d2)=134(a2−d2) Using (1)
a2=9d2
d=±a3=±124
Numbers are 12,8,6 or 6,8,12.
So the Ratio is 2.