Sum means "add" so you add 7.4 and 1.16. Then it asks for a less precise measurement (or apporaxmate) probably meaning after you've rounded up. That would be 9 L or B. Hope that helps!
32/72 because you keep 8/3 and the multiplication sign and then flip the 24/4 to 4/24 and then solve for that and then the simplified answer would be 4/9