top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

What are the next three numbers in sequence 4,6,12,18,30,42,60,72,102,108,?,?,?

+2 votes
1,228 views
What are the next three numbers in sequence 4,6,12,18,30,42,60,72,102,108,?,?,?
posted Mar 9, 2014 by Meenal Mishra

Share this puzzle
Facebook Share Button Twitter Share Button LinkedIn Share Button

1 Answer

+2 votes

The series lists numbers that are flanked by two prime numbers.

4 (3 and 5 are prime)
6 (5 and 7 are prime)
12 (11 and 13 are prime)
18 (17 and 19 are prime)
30 (29 and 31 are prime)
42 (41 and 43 are prime)
60 (59 and 61 are prime)
72 (71 and 73 are prime)
102 (101 and 103 are prime)
108 (107 and 109 are prime)

thus 138 (137 and 139 are prime), 150 (149 and 151 are prime), 180 (179 and 181 are prime)

answer Nov 6, 2014 by Ankit Bajpai
...