Find the time each person takes to walk $\frac{3}{4}$ mile, $\frac{3}{5}$ mile, and $\frac{3}{6}$ mile at the same speed. Actually, the problem states each person walks a certain distance at a rate of 1 mile per hour:

• Joe: $\frac{3}{4}$ mile at 1 mph $\Rightarrow$ $\frac{3}{4}$ hr $= 45$ min
• Tom: $\frac{3}{5}$ mile at 1 mph $\Rightarrow$ $\frac{3}{5}$ hr $= 36$ min
• Alexis: $\frac{3}{6}$ mile at 1 mph $\Rightarrow$ $\frac{1}{2}$ hr $= 30$ min

Total time:

$45 + 36 + 30 = 111 \text{ min} = 1 \text{ hour } 51 \text{ minutes}$