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coolAsk a math question!

 Jun 2, 2017
 #1
avatar+56 
+1


do this

 Jun 2, 2017
 #2
avatar+476 
0

900 possible outcomes, 

ones that have at least 1 zero: every ten and 100-109,200-209,300-309,...900-909

900/10 = 90

90+90=180

 

would this be right?

 Jun 2, 2017
edited by ZZZZZZ  Jun 2, 2017
edited by ZZZZZZ  Jun 2, 2017
edited by ZZZZZZ  Jun 2, 2017
edited by ZZZZZZ  Jun 2, 2017
 #3
avatar+128460 
+1

 

Notice that  in each hundred....we have  [ 10 + 9 ]  =   19  integers that contain at least one zero

 

And there are  9 "blocks" of  "hundreds"   from  100 - 999

 

So.....the probability  is :

 

[ 19 * 9 ]  / [ 999 - 100 + 1 ]  =   171 / 900    =  [ 19/ 100 ]

 

 

cool cool cool

 Jun 2, 2017

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