do u have any idea on this?

question :

let n >=2, 0 < X1< X2 <....< Xn-1 < Xn,

for Xk , k=1,2,....,n to be integers

Define

Sn=(1 + 1/X1)(1 + 1/X2)....(1 + 1/Xn) - 1,

then

i) Show the recurrence Sn-1 = Xn/(Xn+1) Sn - 1

ii)If Sn and Sn-1 are positive integers then Sk is also a positive integer for every k=1,2,3,.....,n