Question

3.75 and a roast beef sandwich cost 3.50

Answer 1

You need to add more detail. this question makes no sense. But if you are asking how much change you would get, the answer is 25 cents.

Answer 2

What part do you need help with? Next time, please make your answer more detailed and understandable. If you wanted to find the difference between 3.75 and 3.50, it would be 25 cents. Hope this helps!