Answer:
B, 1.37
Explanation:
If we're combing, then the first thing you figure out is how much her sister walked and her brother walked combine. Her sister walked 1.23 and her brother walked 0.85, and when you combine you add so add the 2.
1.23 + 0.85 = 2.08 miles
If you want to figure out how much MORE, you must figure out the difference, which means to subtract, so subtract the miles molly walked by the combined number.
3.45 - 2.08 = 1.37 miles
Answer = 1.37 miles (B)