Answer:
Step-by-step explanation:
Answer:
300 doors.
Step-by-step explanation:
1.5 minutes for 1 door.
7.5 hours for 300 doors.
7.5 hours = 450 minutes.
Answer:
12
Step-by-step explanation:
-4 * -3
12
When you multiply two negatives, you get a positive number.
Hope this helps ^-^
Answer:
990 ways
Step-by-step explanation:
The total number of automobiles we have is 11.
Now, what this means is that for the first position , we shall be selecting 1 out of 11 automobiles, this can be done in 11 ways( 11C1 = 11!/(11-1)!1! = 11!/10!1! = 11 ways)
For the second position, since we have the first position already, the number of ways we can select the second position is selecting 1 out of available 10 and that can be done in 10 ways(10C1 ways = 10!9!1! = 10 ways)
For the third position, we have 9 automobiles and we want to select 1, this can be done in 9 ways(9C1 ways = 9!/8!1! = 9 ways)
Thus, the total number of ways the first three finishers come in = 11 * 10 * 9 = 990 ways
