How long will it take to lose 10 pound on an elliptical?

Eating calories are so much faster than burning them off, so any serious attempt at weight loss has to start with controlling your intake.

A snack(say a cupcake) that takes 5 minutes to eat can take 45-60 minutes to burn off.

If you're over eating it's pretty much impossible to exercise hard enough to lose weight through exercise alone.

Start with keeping a food diary. List everything you eat and drink during the day. Figure out how many calories that is. Figure out how many calories you should be eating. Figure out how much you can eat to create about a 500 cal deficiency/day. Start doing it.

Try to add some exercise. One hour daily, at a level that gets you decently sweaty and winded.