数学题请教

PASSWAY

List T consists of 30 positive decimals, none of which is an integer, and the sum of the 30 decimals is S. The estimated sum of the 30 decimals, £, is defined as follows. Each decimal in T whose tenths digit is even is rounded up to the nearest integer, and each decimal in T whose tenths digit is odd is rounded down to the nearest integer; E is the sum of the resulting integers. If of the decimals in T have a tenths digit that is even, which of the following is a possible value of E - S ?

I.-16

II.6

III.10                                    

• AI only
• BI and II only
• CI and III only
• DII and III only
• EI,II, and III
  

这道题题目意思明白了，但是不会做，请会的战友指导下！