Answer: Option 'D' is not correct.
Step-by-step explanation:
Since we have given that
Total distance walked by Adam , Beth, and Carly = 10 miles
Let number of miles Adam walks be a
Let number of miles Beth walks be b
Let number of miles Carly walks be c
According to question,
<u>Beth walked twice as far as Adam </u>
So, the equation will be

Thus, Option 'A' is satisfied.
<u>Now, Beth walked a half a mile further than Carly.</u>
So, the equation will be

Thus, Option 'B' is correct.
Now, we substitute the first equation, then we get

Thus, Option 'C' is correct.
<u>The only incorrect equation is Option 'D' .</u>