Answer: 15 miles
Explanation:
Given : Distance walked by Elena before = 12 miles
After that she walked =


Total distance she waled = (Distance walked by Elena before) + (After that she walked)
i.e. Total distance she waled = 12 miles+ 3 miles
i.e.T otal distance she waled = 15 miles
Hence, she walked 15 miles all together.