How many trailing Zeroes does 53! + 54! have?
Choose the correct choice from the following answers:
A) 12 B) 13 C) 14 D) 15 E) 16
53! + 54! = 53! + 54 * 53!   = 53! (1 + 54)   = 53! * 55   Number of trailing 0s in 53! = number of 5s in the expansion of 53!   = 10 + 2= 
<gadget id="calculator">10 + 2</gadget>
<output>12</output>
12   There is 1 more 5 in 55.   Hence, total number of trailing 0s= 12 + 1= 
<gadget id="calculator">12 + 1</gadget>
<output>13</output>
13   Answer (13)
<result>B</result>
How many trailing Zeroes does 53! + 54! have?