Can you find out a relation and tell which number will suffice the pattern?

Question

In the given figure, you can see that there are four circles numbered from 1 to 4. In the fourth circle, a digit is missing. Can you find out a relation and tell which number will suffice the pattern?

Answer 1

Answer is 2
18 = (5+4) * 2
60 = (12+8) * 3
48 = (9+3) * 4
So
30 = (4+X) * 5
6 = 4+X
X = 2

Answer 2

Ans: 2. Add lower portion numbers and multiply by 2,3,4,5 respectively for 1st circle ,2nd circle and so on

Answer 3

Ans - 2
1. 5+4 = 9*2=18
2.12+8 = 20*3=60
3. 3+9 = 12*4=48
4. 4+2 = 6***5**=30

Answer 4

(30-5*4)/5
=(30-20)/5
=10/5
=2