Each digit 1 through 5 is used exactly once to create a 5-digit integer. If the 3 and the 4 cannot be adjacent digits in the integer, how many 5-digit integers are possible?	Select:
A) 48
B) 66
C) 72
D) 78
E) 90
Total number of 5 digit numbers that can be formed = 5! = 120.   Total number of 5 digit numbers in which 3 and 4 are adjacent = 48. This can be calculated by taking 3 and 4 as a pair and considering positions where they can appear.   Number of 5 digit numbers in which 3 and 4 are not adjacent = Total number of 5 digit numbers - Total number of 5 digit numbers in which 3 and 4 are adjacent.   Ans = 120 - 48= 
<gadget id="calculator">120 - 48</gadget>
<output>72</output>
72   72
<result>C</result>
Each digit 1 through 5 is used exactly once to create a 5-digit integer. If the 3 and the 4 cannot be adjacent digits in the integer, how many 5-digit integers are possible?