Can anyone help me figure out how to answer this?

Bruce is getting materials for a chemistry experiment his teacher gives him a container that has 0.25 liter of liquid in it.bruce need to use 0.4 of this liquid for the experiment. how much liquid will bruce use?

You give a $4 tip for a meal that cost $22. approximately what percent of the bill was your tip?

Ascientist has discovered an organism that produces five offspring exactly one hour after its own birth, and then goes on to live for one week without producing any additional offspring. each replicated organism also replicates at the same rate. at hour one, there is one organism. at hour two, there are five more organisms. how many total organisms are there at hour seven? 2,801 19,531 19,607 97.655