Lets say that we need all logos in a carrousel to be 100px by 100px.
So you have to imagine that you will have a square figure of 100px by 100px and inside of it you will place the logo by scaling it to fit proportionally.
Alain Martínez
If you are a web developer or web designer and a client ask you to develop a responsive web site for sure you have made your self the question: How can I debug mobile web sites?