Identify the graph of f(x)=2(0.5)^x

Which number produces a rationale number when multiplied by 1/5

Bill works as a waiter and is keeping track of the tips he ears daily. about how much does bill have to earn in tips on sunday if he wants to average $22 a day? tips by day tips (dollars) monday tuesday wednesday thursday friday saturday $14 $22 $28 $36

What is the range? can’t seem to find it out