Andrea has one hour to spend training for an upcoming race she completes her training by running ful

[math_celebrity]

Andrea has one hour to spend training for an upcoming race she completes her training by running full speed in the distance of the race and walking back the same distance to cool down if she runs at a speed of 9 mph and walks back at a speed of 3 mph how long should she plan on spending to walk back

Let r = running time. Let w = walking time

We're given two equations

1. r + w = 1
2. 9r = 3w

Rearrange equation (1) by subtract r from each side:

1. w = 1 - r
2. 9r = 3w

Now substitute equation (1) into equation (2):
9r = 3(1 - r)
9r = 3 - 3r

To solve for r, we type this equation into our search engine and we get:
r = 0.25

Plug this into modified equation (1) to solve for w, and we get:
w = 1. 0.25
w = 0.75