Question

Repeat the following procedure for the four given numbers .

Answer 1

3
multiply by 4
12
add 12
24
divide by 2
12
subtract 6
6

number 6 : 6(4) = 24... + 12 = 36...36/2 = 18.....- 6 = 12
number 8 : 8(4) = 32....+ 12 = 44...44/2 = 22....- 6 = 16
number 12: 12(4) = 48....+ 12 = 60...60/2 = 30....-6 = 24

well...by following these steps, it appears the original number doubles as a result.

Answer 2

We do reverse engineering

12 is the quotient. 12 + 6 is 18
18 *2 is equal to 36
36 -12 is equal to 24 
24 divided by 4 is equal to 6. 

N = original number = 6