35.A group of student researchers is working in a wilderness area. Three of them - Pierce, Naomi, and Ikenna -come down with an unidentified illness. There are some typical causes of illness in situations like these: eating contaminated food, drinking impure water, insect bites, etc. The researchers compare what they've consumed, where they've been, what's bitten them, etc. in order to identify the cause of the illness.

All of the researchers have eaten all the same food, but not all of them got sick; so the food probably was not contaminated. Also, everyone has consumed some potentially-contaminated water. The day before the illness started, the team had been moving back and forth between Zone A and Zone B. Ikenna drank water from a natural source in Zone B and remembered getting bug bites in both Zones A and B. Gustavo only drank water from Zone A, but didn't get any bug bites because he wore bug repellent. Yukionly drank water from Zone B, but only gotbug bites in Zone A. Pierce and Naomidrank water from both zonesand got bug bites in both zones.

a) Based on this information, complete the following presence table.

	Contaminated Food	Zone A: Water	Zone B: Bug Bites	Zone B: Water	Zone B: Bug Bites	Unidentified Illness
Gustavo
Ikenna
Naomi
Pierce
Yuki

b) What is the cause of the unidentified illness?

c) Which of Mill's methods did you use to determine the cause?

36. You and two friends, Avery and Errol, all noticed a smattering of tar on your cars. That usually comes from driving on fresh asphalt. You all want to avoid getting more tar on your car, so you compare which major roads you each remember driving on recently.

You remember driving on Waialae, Kapahulu, Kapiolani, H1, and University Ave recently. One friend remembers driving on Kalakaua, Kapiolani, University Ave, and King Street. The other remembers driving on University Ave, Date Street, Kapahulu, and Kapiolani.

a) Complete the presence table belowwith the relevant information that you and your friends have collected.

	Waialae	Kapahulu	Kapiolani	H1	University	Kalakaua	King	Date	Tar
You
Avery
Errol

b) Based on this information, which two streets are the possible sources of the tar?

The three of you then talk to a fourth friend, Carisa, who did not have any tar on her car. She only remembers driving on H1, Waialae, King, and University.

c) Add Carisa's name to the table above along with her information.

d)Based on this information, which street is the source of the tar? How do you know?