Is wp+st>0? 1) ws+pt>0 2) wt+ps>0

[Max@Math Revolution]

Is wp+st>0?

1) ws+pt>0
2) wt+ps>0


* A solution will be posted in two days.

[Max@Math Revolution]

Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.


Is wp + st > 0?

(1) ws + pt > 0
(2) wt + ps > 0


In the original condition, there are 4 variables(w,p,s,t), which should math with the number of equations. So you need 4 equations. For 1) 1 equation, for 2) 1 equation, which is likely to make E the answer.
When 1) & 2), w=3, s=-1, p=-4, t=-1 -> no, w=s=p=t=1 -> yes, which is not sufficient. Thus, the answer is E.