这是天山新13套第一套，我实在是晕。请教各位了～～～

Q6:

B C

xº

yº zº

A D

In the figure shown, line segment AD is parallel to line segment BC. What is the value of x?

(1) y = 50

(2) z = 40

我选c ,key:a （图不知道怎么贴不上啊）

7.A certain university will select 1 of 7 candidates eligible to fill a position in the mathematics department and 2 of 10 candidates eligible to fill 2 identical positions in the computer science department. If none of the candidates is eligible for a position in both departments, how many different sets of 3 candidates are there to fill the 3 positions?

A. 42

B. 70

C. 140

D. 165

E. 315

（我选B KEY:E 这题没看懂。。。我决得就是7×10）

35.Guy’s net income equals his gross income minus his deductions. By what percent did Guy’s net income change on January 1, 1989, when both his gross income and his deductions increased?

(1) Guy’s gross income increased by 4 percent on January 1, 1989.

(2) Guy’s deductions increased by 15 percent on January 1, 1989.

我选C，key:E

7从7个中选1个去数学，而同时从10个中选2去计算机c(7,1)c(10,2)

35设总收入a deduct得为b原来得为a-b上涨后为1.04a-1.15b因为中间是减号，所以没办法比啊，主要是原来得a,b不知道。所以E。