Explanation:

Correct option is 2: 7:72
Logic used is
econd Number = (First number + 1) x (First Number + 2)
The Pattern followed here is:
In 13: 210
(13+ 1) x (13+ 2) = 210 (Second Number)
Similarly,
(7+1) x (7+2) = 72 (Second Number)
Hence, The correct answer is  7: 72.