5-digit numbers divisible by 9 are to be formed by using the digits 0,1,2,3,4,7,8 without repetition, the total number  of such 5-digit numbers formed is $n$, then largest digit in $n$ is 

0+1+2+3+4+7+8=25
 Case(i)excluding 0,7
 i.e sum of remaining digits = 18
 and 5 digited numbers = 5! = 120
 case (ii) Excluding 3,4
 i.e sum of remaining digits = 18
 and 5 digited numbers = 4(4!)=96
 $\therefore$  total numbers of 5 digited numbers div by 9 = 216