Find the number of zero's in the expression 1^1 * 2^2 * 3^3 * 4^4 * 5^5 * ……..10^10. Choose the correct choice from the following answers.
A) 28  B) 15  C) 16  D) 17  E) 81
To find the number of zero's we have to find the powers of 2's and 5's.   Powers of 2's = 2 + 4 + 6 + 8 + 10 = 26   But 4, 8 contains more 2's which are equal to  4 + 8= 
<gadget id="calculator"> 4 + 8</gadget>
<output>12</output>
12   8 contains another eight 2's.   So total 2's= 46   Number of 5's = 5 + 10= 
<gadget id="calculator">5 + 10</gadget>
<output>15</output>
15   So trailing zeroes= 15.   Answer:15
<result>B</result>
Find the number of zero's in the expression 1^1 * 2^2 * 3^3 * 4^4 * 5^5 * ……..10^10.