How many negative numbers are there in an alternating sequence of positive and negative numbers, if the sequence contains b numbers, where b is an odd number greater than 12. The first number of the sequence is a negative number.
Choose the correct choice from the following options:  A) (b-1)/2  B) (b+1)/2  C) b/2  D) b/(2-1)  E) b/(2+1)
Lets put values for b, say b=13 since it's odd and it is grater than 12,   and first number is neg so sequence will be {neg,pos,neg,pos,neg,pos,neg,pos,neg,pos,neg,pos,neg} we can see that it has 7 positive terms   so putting bx=13 in the options,   option (b+1)/2 = (b+1)/2 =&gt; (13+1)/2= 
<gadget id="calculator">(13+1)/2</gadget>
<output>7</output>
7 , the number of positive integers   So, (b+1)/2 is the answer
<result>B</result>
How many negative numbers are there in an alternating sequence of positive and negative numbers, if the sequence contains b numbers, where b is an odd number greater than 12. The first number of the sequence is a negative number.