To find out how many steps Joanna walked in 10 hours, we can first determine her average steps per hour.
Given that she walked 3,000 steps in 24 hours:
\[ \text{Steps per hour} = \frac{3000 \text{ steps}}{24 \text{ hours}} = 125 \text{ steps per hour} \]
Now, to find out how many steps she walked in 10 hours:
\[ \text{Steps in 10 hours} = 125 \text{ steps per hour} \times 10 \text{ hours} = 1250 \text{ steps} \]
So, Joanna walked 1,250 steps in 10 hours.