No. of ways in which any number appearing in one dice = 6
No. of ways in which 2 appear in one dice = 1
No. of ways in which 2 does not appear in one dice = 5
There are 4 dice.
Getting 2 in atleast one dice =
Getting any number in all the 4 dice - Getting not 2 in any of the 4 dice.
$=(6\times 6\times 6\times 6)-(5\times 5\times \times 5\times 5)$