Hey
shubhankarsapaRead the stem very carefully: In
any given 3-day period, what is the probability that the city experiences rain?
So when you multiply for rain for each day, you will get the probability that it will rain all 3 days. But what if it rains the third day and not the first two? It will also be considered under the stem. So we need to find the probability of rain on any day not all days.
Hence we calculate by 1 - no rain = raining at least once.
shubhankarsapa wrote:
Why cant we simply multiply 1/3*1/3*1/3 which is probability of rain for any given day?