Robin can clean
72
7272 rooms in
6
66 days.
how many rooms can robin clean in
9
99 days?

45 rooms

Step-by-step explanation:

well divide 72 rooms by 6 days to find rooms per day then multiply it by 9 to get __ rooms.

72/6 = 8 x 9 = 45

8 rooms per day

5+5 = 10 total marbles

5/10= 1/2 probability of picking a white one first

then you have 9 marbles so a 5/9 chance of picking a black one

1/2 x 5/9 = 5/18 probability of choosing a white then a black marble