A train goin from delhi to jaipur stops at 7 intermediate stations. 5 persons enter the train during the journey with 5 difefrent tickets of same class . How mant different set of tickets they could had??

This is the condition if they al board the train from Delhi, However if they can board the train from any station . so here is the solution

Each person can have two choices 1) Boarding Station 2)Destination

if B.S= Delhi Des=1,2,3,4,5,6,7,Jaipur = 8 choices

if B.S.= 1  Des=2,3,4,5,6,7,Jaipur = 7 choices

if B.S.= 2  Des=3,4,5,6,7,Jaipur = 6 choices

...

thus the total type of tickets that a person can have =8+7+6+5+4+3+2+1 = 36choices

Similarly all the fove people can have these choices (May be recurring) .

Then the total choices may be 36⁵

However if they have different tickets then the permutation possible are 36*35*34*33*32