Question

Sheila either walks or cycles to school. The probability that she walks is 0.65, is she walks the probability she is late is 0.4. If she cycles the probability that she is late is 0.1. Work out the probability that on any one day Sheila will not be late for school

Answer 1

0.705

Explanation:

From the question :

P(not being late) = p(walking and not late) + P(cycling and not late)

P(walking and not being late) = 0.65 * (1 - 0.4) = 0.65 * 0.6 = 0.39

P(cycling and not being late ) = (1 - 0.65) * (1 - 0.1) = 0.35 * 0.9 = 0.315

Hence,

P(not being late) = 0.39 + 0.315 = 0.705