求助GWD2中数学25、29题

仰莎修女

Q25:

A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster.  If a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?

 

A.     0

B.     1/9

C.     2/9

D.     1/3

E.      1

答案是C

Q29:

If 10⁵⁰ – 74 is written as an integer in base 10 notation, what is the sum of the digits in that integer?

 

A.  424

B.  433      

C.     440

D.     449

E.      467

答案是C

fengxiao110

25.（3*2*1）/(3^3)

29.48*9+2+6

仰莎修女

谢谢。知道了

fengxiao110

客气~