Answer: 13.125 miles.
Step-by-step explanation:
Given : The smaller moon of Mars, Deimos, has a diameter of 7.5 miles.
The larger moon, Phobos, has a diameter that is [tex]1\dfrac34[/tex] times greater.
Diameter of Phobos = [tex]1\dfrac34\times\text{(Diameter of Deimos )}[/tex]
[tex]=\dfrac{7}{4}\times7.5 \ \ \ [1\dfrac34 =\dfrac{7}{4}]\\\\=13.125\text{ miles}[/tex]
Hence, the diameter of Phobos = 13.125 miles.
