ok for the first one. since 24/4 is 6 the first answer is correct but since each walk is $6 and 5 walks would get her $30. both answers are correct
then for the second one, you would start with 3 miles per 1 hour (because 6/2 is 3) and then the answer would be 9 miles in 3 hours because if she did 6 miles in 2 hours, 6+3 would be nine. so the last one is correct