What number should replace the question mark?

Answer :

Here we get numbers , As  :

1 ) 8 $\times$  3  =  24 
And
24 +  3  =  27
And
27  $\times$ 2  =  54

2 ) 6 $\times$ 3  =  18
And
18 +  3  =  21
And
21 $\times$ 2  =  42

3 ) 9 $\times$ 3  =  27 
And
27 +  3  =  30
And
30  $\times$ 2  =  60

So,

We get

5  $\times$ 3  =  15 
And
15  +  3  =  18 
And
18   $\times$ 2  =  36