Answer:
27 foot or 324 inches
Explanation:
Given: A 6 foot tall football player casts a 16 inch shadow. At the same time the stadium bleachers cast a 6 foot shadow.
To find: how tall are the bleachers
Solution: 
It is given that a 6 foot tall football player casts a 16 inch shadow.
So, the height of the footballer in inches is 
 inches.
we have the ratio of the height of football player to the shadow is 

Length of shadow in inches is 
 inches.
Now, let the height of the bleachers be h.
So, the ratio of bleachers height to the shadow is 

Since, at the same time the stadium bleachers cast a 6 foot shadow. So, the ratio of height of bleachers to the shadow is same as the ratio of the height of football player to the shadow.
On solving, 

 

 inches or 
 foot
Hence, the height of bleachers is 324 inches or 27 foot.