Hi there! 3 feet = 1 yard, 12 inches = 1 foot and 36 inches = 1 yard. All we have to do is change them up into different units by doing a bit of multiplication, division, maybe mental math, and even proportions if you know how to do them. Regardless on what you do, if you do it correctly, here are what your answers should be for each unit.
Inches
Carol: 42 inches
Tino: 30 inches
Baxter: 54 inches
Feet:
Carol: 3.5 feet
Tino: 2.5 feet
Baxter: 4.5 feet
Yards:
Carol: 1 1/6 yards
Tino: 5/6 yards
Baxter: 1 1/2 yards