Question

A washing machine has the following cycle: soak for 15 minutes, wash for 30 minutes, and rinse for 10 minutes. If you approach the machine at a random during the cycle, what is the probability that the cycle will be in the rinse phase when you arrive at the machine

Answer 1

55 : 100% = 10 : x
55x = 1000%
x = 18.18% [rinse probability]


{more things not in the question}

55 : 100 = 30 : x
55x = 3000
x = 54.54 [wash probability]

55 : 100 = 15 : x
55x = 1500
x = 27.27 [soak probability]