MATH 215 Study Guide - Midterm Guide: Crazy Eights
Document Summary
Math 215/255, sections 101 (rahmani), 102 (froese), 103 (yang) and 104 (daskalakis) Additional instructions: no notes, books or calculators are allowed, read the questions carefully and make sure you provide all the information that is asked for in the question, show all your work. Correct answers without explanation or accompanying work could receive no credit: answer the questions in the space provided. Continue on the back of the page if necessary. Page 1 of 9: a tank with a capacity of 1000 liters contains 500 liters of pure water. 0. 1 kg of salt per liter enters the tank at 10 liters per minute. The contents of the tank are kept thoroughly mixed. Solution: when t t , the volume in the tank is increasing at 2 liters/minute, so t = 500/2 = 250 minutes, and. Solution: the rate of increase of salt is 10 0. 1 = 1 kg/minute. The con- centration of salt in the tank is s(t)/v (t).
