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??

Solution) This is the condition if they all board the train from Delhi, though if they can board the train from any station . so here is the solution

Every 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

...

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

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

Then the total choices may be 365

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