nikhil arora
Last Activity: 13 Years ago
the sum of all given no.s is = 0+1+2+3+4+7+8 = 25 (also this is the maximum sum of digits that can be obtained)
a no will be divisible by 3 if its sum is 24 or 21 or 18 ... so on.
also we have to select 5 digits from 7 digits we have to omit 2 digits
so for a sum of 24 , we have to omit those no which have a sum of 1 i.e.------ 0,1
similarly
for 21 ----we have to omit those which have a sum of 4------ 0,4 or 1,3
for 18 ----- 0,7 or 4,3
for 15 ----- 2,8 or 7,3
for 12 ---- no combination is possible.
we have 7 cases in all.
for three cases the 5 digit no. will not contain 0 so no. of ways ----- 3 *(5!) = 3*120 = 360
for rest four cases , the 5 digit no. will contain 0 hence no of ways.----- 4 * (4x4x3x2x1)= 384
total no of ways = 384 + 360= 744