Problem Solving - 27

In the addition table above, what is the value of m+n?

(A) -19
(B) 4
(C) 5
(D) 6
(E) 22


Answer: C

m = z + 4
n = y + e
m + n = z + 4 + y + e = (z+e) + (4+y) = 10 + (-5) = 5