The integer x is divisible by both 7 and 21. Which of the following must be an integer? Choose the correct option:
A) x/25
B) x/34
C) x/52
D) x/45
E) x/21
Prime factorization of 7 = 1*7   Prime factorization of 21= 3*7   LCM of 7 and 21 = 7 * 3= 
<gadget id="calculator">7 * 3</gadget>
<output>21</output>
21   Therefore x/21 must be an integer   Answer x/21
<result>E</result>
The integer x is divisible by both 7 and 21. Which of the following must be an integer?