Question 1148974
This is a very old problem. Goes back to a gambler by the name of Chevalier de Mere in the year 1717.
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The probability of a double 6 is 1/36
The probability of not getting a double 6 is 35/36
The probability of not getting a double 6 24 times in a row is therefore (35/36)^24.
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Thus, the probability of at least one double 6 in 24 rolls is 1−(35/36)^24 
= 1-0.5085961238691 = 0.4914% 
You can round off to however many decimals they told you to, you didn't say