Did you ever find the answer?
You multiply fractions simply by multiplying numerators and denominators with each other:

<h2>
Height of tree is 7.5 feet</h2>
Step-by-step explanation:
Let t be the height of pole.
Given that the tree is 5 feet shorter than a pole.
Height of pole = t + 15
Also given that the pole is 3 times as tall as the tree.
Height of pole = 3t
So we have
t + 15 = 3t
2t = 15
t = 7.5 feet
Height of tree = 7.5 feet