Answer: He hiked 4/5 miles.
Step-by-step explanation:
Since, the distance he hiked on the lake trail = 3/10 miles
While, the distance he hiked on the the rock trails = 5/10 miles,
Thus, the total distance he hiked
[tex]=\frac{3}{10}+\frac{5}{10}[/tex]
[tex]=\frac{3+5}{10}[/tex]
[tex]=\frac{8}{10}[/tex]
[tex]=\frac{4}{5}\text{ miles}[/tex]
Hence, He hiked 4/5 miles.