***NOTE*** we are going to use the rise over run formula to solve this problem
Joe climbed a mountain with a rise of 1, 200 feet and a run of 1, 500 feet.
So, the slope would be:
1, 200 over 1, 500
which can be simplified...
1,200/1,500 = 12/15 = 4/5
When we solve for slope for Bob, we do the same thing.
He climbed a mountain with a rise 900 feet and a run of 1, 000 feet.
So, it would look like this after we simplify it...
900/1,000 = 9/10
Finally, since Bob's mountain has the largest slope (or fraction), that means that he climbed the steepest mountain.
I hope this helps! :) Let me know if you need help with anything else! I'd be happy to help you!!