A sequence contains y numbers of alternating positive and negative numbers, If the first number is postive and y is an even number, how many negative numbers are in it?  Choose the correct choice from the following choices
A) (y+1)/2 B) (y-1)/2 C) y/(2+1) D) y/(2-1) E) y/2
Lets put values for y, say y=8 since it's even   and first number is positive so sequence will be {pos,neg,pos,neg,pos,neg,pos,neg} we can see that it has 4 negative terms   so putting y=8 in the options,   option y/2 = y/2 =&gt; 8/2= 
<gadget id="calculator">8/2</gadget>
<output>4</output>
4 , the number of negative integers   So, y/2 is the answer
<result>E</result>
A sequence contains y numbers of alternating positive and negative numbers, If the first number is postive and y is an even number, how many negative numbers are in it?