i have 3 dogs and it takes me 3 minutes to walk each dog a mile how long will it take me to walk 67 dogs

If you walk each of them one mile and you walk them simultaneously, it will take you 3 minutes (and a long time to recover).

If you walk them individually, it will take you 3 x 67 or 201 minutes.

Other combinations will result in other answers.

A long time