Abigail's meal cost $16. she gave the server a 20% tip. how much money did abigail give for the tip? a. $3.60 b. $3.20 c. $1.80 d. $1.60

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?