On a certain number line, conditions are a<b<c<d<e and ab>0. Which of the following must be true?
I ab>0 II cd>0 III de>0
Choose the correct choice from the following:
A) I&II only
B) II only
C) III only
D) I only
E) II and III only
Givena<b<c<d<e abcde="" and="">0.   Suppose, for the product to be greater than 0, we can two variables as -ve or four variables can be -ve.   We are given : I ab&gt;0 II cd&gt;0 III de&gt;0   case 1: a and b can be negative/positive and if they are... we get greater than 0.   case 2: we have cd , then c and d both can be negative/positive and if they are... we get greater than 0.   case 2: we have de , then c and d both can be negative/positive and if they are... we get greater than 0.   if cd both negative , then de both have to negative in order to get greater than 0. In order to abcde&gt;0 , cde can't be negative else we get -ve value, then we need to have either a or b as negative then ab can't be greater than 0.   so cde have to be positive.   I only</b<c<d<e>
<result>D</result>
On a certain number line, conditions are a<b<c<d<e and ab>0. Which of the following must be true?
I ab>0 II cd>0 III de>0