You are adding 4 each time, and the terms 1, 2, & 3 are given to you
Note that:
2 (+4) = 6
6 (+4) = 10
10 (+4) = 14
14 (+4) = 18
18 (+4) = 22
22 (+4) = 26
26 (+4) = 30
30 (+4) = 34
34 (+4) = 38
38 (+4) = 42
42 (+4) = 46
46 (+4) = 50
50 is your answer
hope this helps