|
|
if y=9 x can take value 1,2...or 8 ie there are 8 ways of choosing x. similarly z can take values 0,1,...or 8 so there are 9 ways of choosing z
hence the total number of ways of choosing x and z if y=9 is 9*8= 9(9-1)
therefore if y=r (1<r<=9) then the total number of ways of choosing x and z is obviously r(r-1)
so as y takes the values from 2-9 the number of combinations is given as
[2] [ 9] [r(r-1)]
i given the previous ans as [1][ 9] [r(r-1)]. but u get the same ans anyways as 1(1-1)=0.
note- y cant take the val 1 as x cannot be 0 and x<y.
hope i cleared it for u. cheers!!
|
Moderation Team
![[Post New]](/templates/default/images/icon_minipost_new.gif){kind=icon}
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
30
