Question

A message center receives calls from 6 p.m. until 6 a.m. Typically, 50% of the calls come in between 6 p.m. and 9 p.m.; 25% of the calls come in between 9 p.m. and midnight; 20% of the calls come in between midnight and 3 a.m.; and 5% of the calls come in between 3 a.m. and 6 a.m. What is the probability that a call will come in between 6 p.m. and midnight?

Answer 1

total call received between 6 pm and midnight are 75% so 3/4 calls are received till midnight so the probability is 3/4 or 0.75