Subject: mathqa
Question: a hiker walked for 3 days . she walked 18 miles on the first day , walking 3 miles per hour . on the second day she walked for one less hour but she walked one mile per hour , faster than on the first day . on the third day she walked at 7 miles per hour for 2 hours . how many miles in total did she walk ?
Option: 
A: 24
B: 60
C: 62
D: 52
Answer: D