Can we use white sugar, instead of brown sugar? I want to bake a cake but I don't have light brown sugar. Can I replace it with white sugar?
You can substitute white sugar for light brown sugar with no problem, in my experience.

Make sure you substitute by weight (grams/oz), and not by volume(cups/spoons). This is because brown sugar is slightly more dense, so you get more sugar in a cup than you do with light brown.