Answer:

The rock climber climbs 378 feet in 30 minutes
Explanation:
Given,
The rock climber averages 12 and 3/5 feet per minute.
That is, speed of climbing =
ft per min,
Since Distance = speed × time,
If time = 30 minutes,
So, the distance, x, in feet covered by climber,




Hence, The rock climber climbs 378 feet in 30 minutes