Answer:
0.784
Explanation:
let's work backward.
The probabilty it will rain each day is 40%, so probabilty of dry weather is 1 - 40% = 60%
Probability of dry weather 3 day = 0.6*0.6*0.6 = 0.216
Hence, probability it will rain at least one of the 3 days = 1 - 0.216 = 0.784