can you help me please?

Question

You are drilling a well. The geological survey indicates there will be two main types of rock; one type is considerably harder than the other. You will be able to drill through the softer rock at a rate of 5 feet per hour and through the harder rock at 3 feet per hour. The total depth of the rock is 485 feet.

Let x=the number of hours drilling through the hard rock and y=the number of hours drilling through the soft rock.

Answer 1

5x = distance drilled through soft rock

3y = distance drilled through hard rock

 

5x + 3y = 485

Answer 2

I want to point out that you'll need to ensure x is for hard rock and y is for soft rock, as the instructions appear to conflict in the last 3 sentences !