Answer:
feet
Explanation:
Let height of mandy be m, sophia be s, and alexis be a
"sophia is 3/4 as tall as mandy":

"alexis is 5/6 as tall as mandy":

Since mandy is 5 feet, we plug in 5 into m in both of the equations to find height of alexis and sophia.
Sophia =

Alexis =

Difference in height of Alexis and Sophia is
feet