The answer is:
a) 300
b) 600
c)

d)

e) 2400
The explanation is shown below:
1. You have that the total number of vertical feet that a climber has traveled (which you can call
), varies directly with the number of hours she has been climbing (which you can call
), and the constant of proportionality is 600 (
).
2. Keeping this on mind you can express it as following:

3. Now, substitute the values given in the table and solve for
to calculate the number of feet or solve for
to calculate the time in hours:
a)

b)

c)

d)

e)
