Question 994679
probability of one being not rotten is 0.7.
Exactly 1 is 7(0.7)^1(0.3)^6, the 7 being the number of ways it can be chosen, first, second, third, fourth, fifth, sixth, or seventh.
=0.00357
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for at least one is rotten: Probability none is rotten and subtract that from 1.  That is easier than calculating 1,2,3,4,5,6,7.
The probability that none is rotten is 0.7^7=0.0824
The probability that at least one is rotten is the complement, or 0.918