Answer:
there is a problem you never gave a number of star stickers so i can't answer
Step-by-step explanation:
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:



This one could be 8/10, or 4/5 simplified
Answer:
There are 220 students at Marie's school :)