Question

what is the probability that a number been picked from one to hundred is divided by 3 but not by 9​

Answer 1

Step-by-step explanation:

I can classify all natural numbers not divisible by 9 into 8 different classes depending on the remainder they leave when divided by 9 as 9m+1,9m+2...9m+89m+1,9m+2...9m+8 out of these only 9m+39m+3and 9m+69m+6 are multiples of 3 hence probability is 28=1428=14.Here all these classes are equally likely.