Question

Which number goes in the square with the question mark?

[?] ÷ 3 = 2 N
N = 21 ÷ 3-3
A. 0
B.7
C.8
D.24

Answer 1

this has to do with trial and error

since N=21÷3-3

so 21÷3-3=4

therefore N=4

substitute for N

2×4=8

8×3=24

therefore 24÷3=2×4