Answer: 7 days
Explanation:
Camille and Hiroki have decided to start walking for exercise. Camille is going to walk 7 miles the first day and 3 miles each day after that. Hiroki is too busy to walk on the first 2 days, so he decides to walk 5 miles each day until he has walked the same number of miles as Camille.
Camille will walk x days, so: 7 + 3(x-1) miles
Hiroki will walk the same miles, but 2 days less so: 5(x-2)
same amount of miles:
5(x-2) = 7 + 3(x-1)
5x - 10 = 7 + 3x - 3
5x - 3x = 10 + 7 - 3
2x = 14
x = 7
If Camille and Hiroki will have walked the same number of miles, how many days will Camille have walked?
Camille will have walked 7 days.