Question 1138214
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{{{highlight(cross(Five))}}} <U>Six</U> cards numbered with the digits 3,4,5,6,7,8 are shuffled and laid in a row to make a five-digit number. 
What is the probability that this number is divisible by 9?
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<pre>

3 + 4 + 5 + 6 + 7 + 8 = 33.


a)  33 - 3 = 30

b)  33 - 4 = 29

c)  33 - 5 = 28

d)  33 - 6 = 27

e)  33 - 7 = 26

f)  33 - 8 = 25.



So, we have 6 cases (6 sums), and we see that among the sums of any 5 cards, only one is divisible by 9 : 
it is case d), where the sum is 27.


Therefore, the probability under the question is  {{{1/6}}}.
</pre>

Solved and answered.