ALL UNITS IN THOUSANDS.
X8 = 130
Consider that X1 to X7 are also 130 and X9 to X15 are 170 (For the most close case in which values of X9 to X15 will be minimum). In this case if decrease any of the value from X1 to X7 (or X9 to X15) then value of X15 will increase more. There is no way by which we can decrease the value of X15 (Highest) without making any other value to be more than X15.
So statement 1 is always true.
Statement 2 is not always true. (One example is case taken above)
Statement 3 is not always true (One example is case taken above)
SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008