Probability Practice Test 1

Probability that LPG will last ≥ 60 days = 0.8 ∴ Probability that the LPG will last < 60 days = 1 - 0.8 = 0.2
Probability that the LPG will be last ≤ 90 days = 0.6.
∴ The probability that the LPG will last ≥ 60 days and ≤ 90 days will be = (probability that the LPG will last ≤ 90 days) - (probability that a LPG will last < 60 days) = 0.6 - 0.2 = 0.4