Answer:
15
Step-by-step explanation:
If the depth is 10 inches and the slope is 3/4 or less, then the height is a maximum of ...
(10 in)(3/4) = 7.5 in
The number of steps in 9 feet must be at least ...
(9 ft)×(12 in/ft)/(7.5 in/step) = (108/7.5) steps = 14.4 steps
14 steps will make the slope greater than 3/4, so Brianne must plan on at least 15 steps.
