Because the number is even, then the number of possible combinations will be: 110/2 = 55 let's consider a simpler example, the number: 10, then we have: 10+0, 9+1, 8+2, 7+3, 6+4, which is equal to 10/2 =5 combinations. Note: We are not considering permutations between the elements of the sum therefore 10+0, 0+10 counts as one combination.
Answer: see below
Step-by-step explanation
Let 2 + a = 11 x
Let 35 - b = 11 y
Where x and y are any unknown integer
subtract the two equations
- 33 + a + b = 11 (x+y)
a+ b = 11 (x+ y) +33
a+ b = 11 (x+y) + 3 (11)
a+ b = 11(x+ y+3)
Which proves that a+b is a factor of 11
