各位NN看几道数学 谢谢

scholar

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person.What is the charge for each additional person?

(1)The daily cost per person for 4 people sharing the cost of a room equally is $45.

(2)The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people. D





A photographerwill arrange 6 people of 6 different heights for photograph by placing them in two rows of three so that each person in the first row is standing in front of someone in the second row.The heights of the people within each row must increase from left to right, and each person in the second row must be taller than the person standing in front of him or her.How many such arrangements of the 6 people are possible?



A.5

B.6

C.9
D.24
E.36
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