A 911-Response Centre can dispatch police (C), EMTs (E), or firefighters (F) to emergency calls. Among their received calls, records indicate that:
• 55% of calls required police,
• 71% of calls required EMTs,
• 91% of calls required police or EMTs,
• 73% of calls required police or firefighters,
• 82% of calls required EMTs or firefighters,
• 5% of calls required none of the three services.
E F
C
(a) What is the probability that a random call requires exactly 1 of the 3 services?
Hint: Use the Venn diagram and think about what regions each of the given events occupy.