请教数学GWD1

竟然有5道不会，请各位帮忙。谢谢

A.       0

B.        1/9

C.        2/9

D.       1/3

E.        1

Q10:

A set of numbers has the property that for any number t in the set, t + 2 is in the set.  If –1 is in the set, which of the following must also be in the set?

I.                    -3

II.                 1

III.               5

A.    I only

B.    II only

C.    I and II only

D.    II and III only

E.    I, II, and III

Q17:

In Town X, 64 percent of the population are employed, and 48 percent of the population are employed males.  What percent of the employed people in Town X are females?

A.     16%

B.      25%

C.      32%

D.     40%

E.      52%

Q26:

Running at their respective constant rates, machine X takes 2 days longer to produce w widgets than machine Y.  At these rates, if the two machines together produce 5/4 w widgets in 3 days, how many days would it take machine X alone to produce 2w widgets?

A.     4

B.      6

C.      8

D.     10

E.      12

Q31:

A positive integer n is said to be “prime-saturated” if the product of all the different positive prime factors of n is less than the square root of n.  What is the greatest two-digit prime-saturated integer?

A.     99

B.      98

C.      97

D.     96

E.      95

Hi I may have the answers for 10, 17, 26.

10) -1+2=1,1+2=3, 3+2=5...

17) 16/64=.25 u might want to read the question carefully

26) use the fomula 1/y+1/(2+y)=5w/12

btw, anyone knows at most how many incorrect answers could lead to math 50+? thanks~

应该错一个，50＋