IMO C because:
1)y < z < x now W can be <y or >x. NOT SUFF
2)we need information about others to decide. NOT SUFF
combining
if x is twenty five. y and z must be less than 25 percent. W must be >25 to get 100 percent

Posted: Fri Jul 03, 2009 4:16 am Post subject: Four dollar amounts
Four dollar amounts, w, x, y, and z, were invested in a business. Which amount was greatest'?
(1) y < z < x
(2) x was 25 percent of the total of the four investments.


I think answer should be C.
Statement 1 does not tell you anything about w, so thts easy.
Statement 2 just tells you that x=25% but we still dont know if it was w or y or z which may be 33% or 28% right?
Lets use them together, we know that x>y>z AND that x=25% or 1/4th of the investments and also that y and z MUST be lesser than 25% or 1/4th of the investment. This ensures that w MUST be the largest investment. Lets plug in values. Lets say business investment is 100 dollars, then x=25 dollars and y and z are anything LESS than 25 dollars, ie lets say 24 each..so 25+24+24=73 leaving w as 27% of investment. simple! :)