which number replaces the question mark?
A
12
B
6
C
9
D
8
Correct Answer: 6
4 = 6 - 2 6 = 9 - 3; 2 = 3 - 1 9 = 19 - 10; 3 = 10 – 7 ∴1 = 7 - ? = ? = 6