A sequence contains an alternation of positive and negative numbers. The sequence contains x numbers, and begins with a positive number. How many positive numbers are in it If x is an odd number?
Choose the most appropriate option:  A) (x+1)/2  B) x/3  C) x/(2-1)  D) x/(2+1)  E) (x-1)/2
Lets put values for x, say x=7 since it's odd   and first number is neg so sequence will be {pos,neg,pos,neg,pos,neg,pos} we can see that it has 4 positive terms   so putting x=7 in the options,   option (x+1)/2 = (x+1)/2 =&gt; (7+1)/2= 
<gadget id="calculator">(7+1)/2</gadget>
<output>4</output>
4 , the number of positive integers   So, (x+1)/2 is the answer
<result>A</result>
A sequence contains an alternation of positive and negative numbers. The sequence contains x numbers, and begins with a positive number. How many positive numbers are in it If x is an odd number?