Answer:
Step-by-step explanation:
You can start by doing 3×3 which is 9 than get the 9 and multiply it by 11 which would be 99
Answer:
a) For this case we define the random variable as X ="waiting time during peak hours" and we know that this distribution follows an uniform distribution:

Where a and b represent the limits of the distribution.
b) 
And the height for this case would be 0.125
Step-by-step explanation:
Part a
For this case we define the random variable as X ="waiting time during peak hours" and we know that this distribution follows an uniform distribution:

Where a and b represent the limits of the distribution.
Part b
For this case the density function would be given by:

And the height for this case would be 0.125
And
for other case.
The cumulative distribution function would be given by:



The sum of the numbers is 20 10+10=20 20/2=10
2 students more were introducced in the class and each group had 8 people