The number 1,2,3,4,...,7 are randomly
divided into two non −empty subsets.
The probability that the sum of the
numbers in the two subsets being
equal is (r/s) expressed in the lowest
term. Find r+s ?
A five digits number divisible by 3
is to be formed using the number
0,1,2,3,4 and 5 without repetition
The total number of ways this can
be done is __