1&2&3&4
───1(1,1)&(1,2)&(1,3)&(1,4)
───2(2,1)&(2,2)&(2,3)&(2,4)
───3(3,1)&(3,2)&(3,3)&(3,4)
───4(4,1)&(4,2)&(4,3)&(4,4)
sample space = 16
sum of nos. removed are (2), 3, (4), 5
3, (4), 5, (6)
(4), 5, (6), 7
(5), 6, 7, (8)
Even nos. = 8 of them
Pr(even sum) =
=