Ayuda porfa con resolución y explicación :(

Neveah and clint are baking muffins for the bake sale. they need to bake 30 muffins for their display case. clint has baked 4 so far, and neveah has baked 7. how many muffins (m) do they have left to bake? show your work!

How do you use the elimination method for this question? explain, because i really want to understand!

17 in long 1.3 ft wide and 8in high what is the volume